Boron doped diamond electrode and preparation method and applications thereof

Abstract

A boron doped diamond electrode and its preparation method and application, the electrode is deposited with a boron or nitrogen doped diamond layer or a boron or nitrogen doped diamond layer composite layer on the surface of the electrode substrate, or after a transition layer is disposed on the surface of the substrate, a boron or nitrogen doped diamond layer or a composite layer of boron or nitrogen doped diamond layer is disposed on the surface of transition layer. The preparation method is depositing or plating a boron or nitrogen doped diamond layer on the surface of the electrode substrate, or providing a transition layer on the surface of the electrode substrate, and then depositing or plating a boron or nitrogen doped diamond layer or a composite layer of boron or nitrogen doped diamond layer on the surface of the transition layer.

Claims

1. A boron doped diamond electrode, comprising an electrode substrate, a transition layer arranged on the surface of the substrate, a layer of boron doped diamond arranged on the surface of the transition layer, metal particles distributed on the surface of the diamond layer, and micropores and/or sharp cones distributed on the surface of the diamond layer, wherein material of the metal particles is selected from iron, cobalt or nickel, wherein at least a portion of the micropores are not embedded with the metal particles, and material of the micropores and/or the sharp cones is solid carbon, wherein the surface of the diamond layer has a pore size ranging from 9 μm to 5 mm, and a tip diameter ranging from 1 μm to 30 μm.

2. The boron doped diamond electrode according to claim 1, wherein graphene or/and carbon nanotube layer are deposited on the surface of the diamond layer having the micropores and/or the sharp cones.

3. A method of preparing the boron doped diamond electrode according to claim 1, comprising the steps of: step 1, depositing a boron or nitrogen doped diamond layer, comprising: after an intermediate transition layer is prepared on a surface of an electrode matrix, it is placed in a suspension composed of nanocrystalline and/or microcrystalline diamond mixed particles, and after the nanocrystalline and/or microcrystalline diamond particles are dispersed evenly and embedded on the surface of the electrode matrix by using ultrasonic oscillation, the electrode matrix is removed and dried to form an electrode substrate and a transition layer arranged on the surface of the electrode substrate, and then depositing the boron doped diamond layer in the chemical vapor deposition furnace; or after an intermediate transition layer is prepared on a surface of an electrode matrix, one method of spray atomization and electrostatic adsorption is used to grow a nanocrystalline and/or microcrystalline diamond seed on the surface of the electrode matrix to form an electrode substrate and a transition layer arranged on the surface of the electrode substrate, and then depositing the boron or nitrogen doped diamond layer in the chemical vapor deposition furnace; the deposition process parameters are: the carbon-containing gas accounts for 0.5-10.0% of the total mass flow rate of the gas in the furnace; the growth temperature is 600-1000° C., the growth pressure is 10.sup.3-10.sup.4 Pa; the boron source is one of solid, liquid, and gaseous boron sources; step 2, preparing micropores and/or sharp cones on the surface of boron doped diamond layers, comprising: a first metal layer having a higher catalytic ability for carbon is deposited on the diamond surface obtained in the first step by magnetron sputtering or electroless plating, and the boron doped diamond layer deposited with the first metal layer is subjected to a first high temperature heat treatment, so that the first metal layer is spheroidized at high-temperature, metal nanospheres and/or micron spheres with mass distribution are formed on the surface of diamond; at high temperatures, the carbon atoms in the diamond are continuously dissolved in the metal nanospheres or microspheres, and the metal nanospheres or the solid carbon precipitated by supersaturating the carbon atoms in the metal nanospheres or microspheres are added by adding hydrogen gas, so that the metal nanospheres or microspheres continuously migrate into the interior of the diamond, eventually forming a large number of micropores and/or sharp cones on the surface of the diamond; material of the first metal layer is selected from one or a composite of metal iron, cobalt, nickel; the first high-temperature heat treatment temperature is 600-1000° C., the treatment time is 1 min-3 h, the furnace atmosphere is selected from one or a mixture of CH.sub.4, H.sub.2, N.sub.2, Ar gas, and the pressure in the furnace is 0.1-1 atm.

4. The method of preparing the boron doped diamond electrode according to claim 3, wherein a second metal layer that does not form carbides and does not dissolve carbon atoms at a high temperature is prepared on the surface of the diamond which has a large number of microporous and/or sharp cones formed thereon, and then the second metal layer is spheroidized into nano-metal spheres and embedded in the micropores by a second high-temperature heat treatment in a protective atmosphere or a vacuum; metal of the second metal layer is selected from one or a combination of ruthenium, platinum, gold, silver, copper, palladium, iridium; the second high-temperature heat treatment temperature is 600-1000° C., the time is 1 min -3 h, the furnace atmosphere is selected from one or a mixture of vacuum, N.sub.2, Ar gas, and the pressure in the furnace is 0 Pa -1 atm.

5. The method of preparing the boron doped diamond electrode according to claim 3, wherein the chemical vapor deposition is used to deposit graphene or/and carbon nanotube layers on the surface of diamond layers with micropores and/or sharp cones; specific deposition process parameters are: depositing graphene coated with boron doped diamond layer composite layer: the deposition parameters are as follows: the carbon-containing gas accounts for 5-80% of the total mass flow rate of the gas in the furnace; the growth temperature is 400-1200° C., the growth pressure is 5-10.sup.5 Pa; the plasma current density is 0-50 mA/cm.sup.2; the magnetic field strength in the deposition area is 100 G to 30 T; depositing carbon nanotubes coated with boron or nitrogen doped diamond layer composite layer: the deposition parameters are as follows: the carbon-containing gas accounts for 5-50% of the total mass flow rate of the gas in the furnace; the growth temperature is 400-1300° C., the growth pressure is 10.sup.3-10.sup.5 Pa; the plasma current density is 0-30 mA/cm.sup.2; the magnetic field strength in the deposition area is 100 G to 30 T; depositing carbon nanotubes/graphene coated with boron doped diamond layer composite layer: carbon nanotubes are first deposited, and the deposition parameters are as follows: the carbon-containing gas accounts for 5-50% of the total mass flow rate of the gas in the furnace; the growth temperature is 400-1300° C., the growth pressure is 10.sup.3-10.sup.5 Pa; the plasma current density is 0-30 mA/cm.sup.2; the magnetic field strength in the deposition area is 100 G to 30 T; then graphene is deposited, and the deposition parameters are as follows: the carbon-containing gas accounts for 5-80% of the total mass flow rate of the gas in the furnace; the growth temperature is 400-1200° C., the growth pressure is 5-10.sup.5 Pa; the plasma current density is 0-50 mA/cm.sup.2; the magnetic field strength in the deposition area is 100 G to 30 T.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram of the device structure for treating organic sewage according to the present invention.

(2) FIG. 2a is the surface SEM morphology of boron doped diamond film prepared in Example 13;

(3) FIG. 2b is the surface SEM morphology of boron doped diamond film prepared in Example 13 which is formed by catalytic etching with metal nickel at 700° C.;

(4) FIG. 2c is the surface SEM morphology of boron doped diamond film prepared in Example 13 which is formed by catalytic etching with metal nickel at 800° C.;

(5) FIG. 2d is the surface SEM morphology of boron doped diamond film prepared in Example 13 which is formed by catalytic etching with metal nickel at 900° C.;

(6) FIG. 2e is the surface SEM morphology of boron doped diamond film prepared in Example 13;

(7) FIG. 2f is the surface SEM morphology of boron doped diamond film prepared in Example 13 which is formed by catalytic etching with metal nickel at 700° C. and the nickel has been removed by dilute nitric acid;

(8) FIG. 2g is the surface SEM morphology of boron doped diamond film prepared in Example 13 which is formed by catalytic etching with metal nickel at 800° C. and the nickel has been removed by dilute nitric acid;

(9) FIG. 2h is the surface SEM morphology of boron doped diamond film prepared in Example 13 which is formed by catalytic etching with metal nickel at 900° C. and the nickel has been removed by dilute nitric acid;

(10) FIGS. 3a-3h are the SEM image and EDX spectra of the surface morphology of BDD/CNT film which has catalyzed growth after different Ni sputtering time prepared in Example 14;

(11) In FIGS. 3a-3h,

(12) FIG. 3a is the SEM image of BDD/CNT film surface which has catalyzed growth after sputtering nickel for 15 s, and FIG. 3b is an enlarged drawing of FIG. 3a;

(13) FIG. 3c is the SEM image of BDD/CNT film surface which has catalyzed growth after sputtering nickel for 30 s, and FIG. 3d is an enlarged drawing of FIG. 3c;

(14) FIG. 3e is the SEM image of BDD/CNT film surface which has catalyzed growth after sputtering nickel for 60 s, and FIG. 3f is an enlarged drawing of FIG. 3e;

(15) FIG. 3g is the SEM image of BDD substrate surface;

(16) FIG. 3h is the EDX spectra of BDD/CNT film surface which has catalyzed growth after sputtering nickel for 15 s.

(17) FIGS. 4a-4f are the surface SEM morphology of diamond/carbon nanotube composite film which grows at different concentrations of methane (CH.sub.4/(CH.sub.4+H.sub.2)) prepared in Example 15.

(18) In FIGS. 4a-4c, the SEM image of diamond/carbon nanotube composite film obtained by catalytic growth of 0.5%, 5%, 10% methane concentration respectively;

(19) FIGS. 4d-4f is the Raman spectrum of the composite film corresponding to FIGS. 4a-4c.

(20) In the drawings:

(21) In FIG. 1,

(22) 1—Regulated DC power supply, 2—Stainless steel electrode, 3—Foam substrate BDD electrode, 4—Electrolyzer, 5—Peristaltic pump, 6—Beaker.

(23) In FIG. 2,

(24) From FIGS. 2a to 2d, it can be seen that a small amount of agglomeration occurs at 700° C., and the nickel film is still completely covered on the diamond surface; When the temperature rises to 800° C., the nickel film further agglomerates, grows and forms strips, finally, the nickel strips are connected to each other to form a metal nickel net covering the diamond film; When the temperature rises to 900° C., nickel agglomeration becomes serious, and only a small amount of nickel strips is left on the diamond surface, which can be seen from the surface exposed after nickel film agglomeration that the original morphology of diamond has changed obviously.

(25) FIGS. 2e-2h are the SEM morphology of diamond films at various temperatures treated by dilute nitric acid for removing nickel. It can be seen from the image that the diamond films are etched more and more seriously with the increase of temperature. At 700° C., the diamond films are partly etched, and exist many uneven protrusions in some serious etched areas, while the other parts still maintain the original diamond morphology; At 800° C., the etching degree is intensified, the bulk diamond is not seen on the surface, and all the regions are etched into protuberance with different length-diameter ratios; When the temperature rises to 900° C., diamond on the surface is completely etched, and the protuberance formed at low temperature becomes another foam-like porous structure.

(26) In FIGS. 3a-3h,

(27) FIGS. 3a-3f are the SEM morphological image and its magnification of BDD/CNT (carbon nanotube) composite film which has catalyzed growth after different sputtering Ni time. By comparing the surface morphology of the film before and after Ni catalyzes growth, the typical diamond morphology is not seen on the BDD surface after Ni film catalyzes growth, and the BDD surface was covered with a thick layer of carbon nanotubes (CNTs). Further comparing the surface morphology of BDD/CNT composite film which has catalyzed growth after different sputtering Ni time, it is found that different sputtering Ni thickness has a great influence on the catalytic growth of carbon nanotubes (CNTs). When the sputtering time of Ni is shorter (15 s), the surface of the electrode is covered with a layer of tubular catalytic products, and they are equally distributed, interlaced and superimposed on the electrode surface. The surface morphology of the film has been completely changed and accompanied by the agglomeration of Ni nanoparticles (FIGS. 3c-3d); When the sputtering time of Ni is 30 s, the carbon nanotube coverage on the surface of BDD/CNT composite film decreases, the initial BDD morphology of some regions begins to appear and the length of the tubular catalytic product increases (FIGS. 3c-3d); When the sputtering time of Ni is 60 s, the carbon nanotube coverage on the surface of BDD/CNT composite film decreases further, the initial BDD morphology of most regions is exposed, and the length of the carbon nanotubes catalyzed grown is further increased (FIGS. 3e-3f).

(28) In FIG. 4a-4f,

(29) FIGS. 4a-4c are the SEM morphology of boron-doped diamond/carbon nanotube composite film grown with different methane concentration. It can be seen from the figure that the surface of the original diamond has changed to varying degrees under different methane concentration, and with the increase of methane concentration, the change became more and more obvious, and the number of carbon nanotubes was also increasing. FIG. 4a shows the morphology of diamond surface catalyzed growth by low methane concentration (0.5%). The nickel film on diamond surface produces a certain degree of agglomeration at high temperature and forms a small amount of dispersed agglomeration particles. However, because the concentration of methane did not reach the required concentration of nanotube formation, no catalytic products of tubular morphology were found on the whole surface. It can be seen from the figure that the grain facet on the surface of the film is very clear, and the surface morphology of the original diamond is still maintained. When the concentration of methane increased to 5%, some changes have taken place on the surface of the film. Although the diamond still maintained the original particle morphology, the edge facet of the diamond has become blurred. As can be seen from the amplified FIG. 4b, the diamond surface has been completely covered by short carbon nanotubes about 20 nm in diameter. As the catalytic methane concentration increases to 10% (FIG. 4c), the carbon nanotubes (CNTs) grow further and are interlaced with each other on the diamond surface, and the original diamond morphology on the film surface has been completely changed due to the carbon nanotubes covering.

(30) FIGS. 4d-4f show the Raman spectra of the samples obtained under different catalytic concentrations, which Gaussian multimodal fitting was performed, and specific parameter value. It can be seen from the figure that with the increase of the catalytic concentration, the Raman spectra shows a significant change. When the concentration of catalytic methane is 0.5%, there are mainly four characteristic peaks in the spectrum line which is 1332 cm.sup.−1, 1350 cm.sup.−1, 1580 cm.sup.−1 and 2700 cm.sup.−1, respectively. The highest peak at 1332 cm.sup.−1 is the characteristic peak of diamond phase (Dia peak). The low “steamed bread peak” at 1350 cm.sup.−1 and 1580 cm.sup.−1 is the graphite peak mainly caused by sp.sup.2 phase, which is generally called the graphite D peak and G peak. The little dwarf peak at 2700 cm.sup.−1 in the high frequency band of the spectrum line is the second order characteristic peak of graphite phase, which is called 2D peak. The Raman spectrum showed that the samples grown under low concentration were mainly diamond phase, and the content of sp.sup.2 phase such as graphite was low. When the catalytic methane concentration increases continually, the spectral line of samples with 5% and 10% methane concentration changed obviously comparing with those low methane concentration. There are two sharp sp.sup.2 characteristic peaks of 1350 cm.sup.−1 (D peak) and 1600 cm.sup.−1 (G peak) in the high concentration catalytic samples, which indicates that there is a large amount of graphite phase in the sample. The results of SEM show that the graphite phase is indeed carbon nanotube morphology. In many studies, the ratio of D peak to G peak (I.sub.D/I.sub.G) is generally used to measure the graphitization state of disordered carbon materials. The smaller the strength ratio is, the higher the graphite quality of the sample is. The I.sub.D/I.sub.G values of samples with 5% and 10% methane concentration measured by this example are 0.93 and 0.89 respectively. This result shows that the composite membranes have better graphite structure with the increase of catalytic concentration. In addition, the other four dwarf peaks appeared in the two kinds of catalytic samples with high methane concentration: the 1332 cm.sup.−1 peak was low and the width of half height was large, which indicated that the diamond phase in the sample was very small; The 1580 cm.sup.−1 and 1600 cm.sup.−1 belong to the G peak of graphite, and this multi-peak structure occurs because graphene sheets curl into cylindrical tubes when carbon nanotubes are formed. In this case, there will occur symmetry damage caused by tangential Raman vibration of graphite and quantum confinement effect of phonon wave loss along the circumferential direction of carbon nanotubes. However, the general large diameter multi-walled carbon nanotubes have a continuous diameter distribution, which the asymmetric characteristics of the G band are weak and will not appear as 5-6 G peak splits like single-walled carbon nanotubes, but appear a Raman peak near the graphite frequency of 1580 cm.sup.−1. In addition, the 2700 cm.sup.−1 (2D) and 2900 cm.sup.−1 (D+G) peaks in high frequency range can further confirm the existence of carbon nanotubes in the samples.

DESCRIPTION OF THE EMBODIMENTS

Example 1

Sponge+Magnetron Sputtering Nb+Burn Off the Sponge to get the Foam Nb+Ultrasonic Seeding+Electrostatic Adsorption+BDD

(31) (1) Depositing a metal niobium foam skeleton on the surface of a sponge foam substrate using magnetron sputtering. The sponge matrix has a pore size of 0.1 mm, an open cell ratio of 50%, and a uniform or random distribution of pores, which is a three-dimensional structure. After the deposition is completed, the sponge is burned at a high temperature to obtain foam niobium.

(32) (2) The foam niobium substrate (3 cm×2 cm×0.3 cm) obtained by step (1) was placed in the suspension of the mixture of nanocrystalline and microcrystalline diamond particles to be oscillated and dispersed evenly in ultrasonic wave, which finally get a foam skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh.

(33) (3) Depositing diamond film on the foam niobium substrate obtained in the step (2) by HFCVD, the deposition process parameters are as follows: the distance of 6 mm from hot filament to substrate, the substrate temperature of 850° C., the hot filament temperature of 2200° C., the deposition pressure of 3 kPa, the deposition time of 6 hours, and the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 of 0.2:1:99; Then, three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode has a grain size of about 10 μm, which is successively decreased toward the core, and the core grain size is about 300 nm.

(34) (4) The boron doped diamond electrode prepared in step (3) is encapsulated, and use the stainless steel electrode as cathode. After connecting the power supply, it was placed in an electrolytic cell having a capacity of 1 L, and the dye was reactive orange X-GN having a concentration of 100 mg/L. The apparatus used for treating organic sewage is shown in the attached drawing (1).

(35) (5) The current density during the degradation process is 100 mA/cm.sup.2, the supporting electrolyte is sodium sulfate, the concentration is 0.1 mol/L, using sulfuric acid to adjust the solution pH to 3, and the speed of peristaltic pump is 6 L/h. After degradation for two hours, the color removal rate of the dye reached 99%, which was completely degraded.

Example 2

Sponge+Magnetron Sputtering Niobium+Ultrasonic Seeding+Electrostatic Adsorption+BDD

(36) (1) A metal niobium foamed skeleton was deposited on the surface of a sponge foamed substrate by using magnetron sputtering. The sponge matrix has a pore size of 0.1 mm, the opened cell ratio of 50%, a uniform distribution of pores or random distribution, the sponge matrix had a three-dimensional structure.

(37) (2) The foamed niobium substrate (having a size of 3 cm×2 cm×0.3 cm) obtained in the step (1) was placed in a suspension of the nanocrystalline and microcrystalline diamond mixed particles, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh was obtained.

(38) (3) The diamond film was deposited on the foamed niobium substrate that was obtained in the step (2) by hot filament chemical vapor deposition, the deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 850° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 6 hours, and the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 10 μm, decreasing in turn toward the core, and the core grain size was about 300 nm.

(39) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using the stainless steel electrode as the cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the active orange X-GN with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(40) (5) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the rotational speed of the peristaltic pump was set to 6 L/h. After two hours of degradation, the color removal rate of the dye reached 97%, the basic degradation was complete.

Example 3

Sponge+Magnetron Sputtering Titanium+Magnetron Sputtering Niobium+Ultrasonic Seeding+Electrostatic Adsorption+BDD

(41) (1) A metal titanium foamed skeleton was deposited on the surface of the sponge foam substrate by using magnetron sputtering, and then the metal niobium was magnetron sputtered on the surface of the titanium. The sponge matrix had a pore size of 0.1 mm, the opened cell ratio of 80%, the pores were evenly distributed or randomly distributed, the sponge matrix was a three-dimensional structure.

(42) (2) The foamed metal substrate (having a size of 3 cm×2 cm×0.3 cm) obtained in the step (1) was placed in a suspension of the nanocrystalline and microcrystalline diamond mixed particles, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh was obtained.

(43) (3) The diamond film was deposited on the foamed metal substrate that was obtained in the step (2) by hot filament chemical vapor deposition. The deposition process parameters were as follows: the hot filament is 8 mm from the substrate, the substrate temperature is 800° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 12 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.4:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 20 μm, decreasing in turn toward the core, the core grain size was about 400 nm.

(44) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using stainless steel electrode as the cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the active blue KN-R with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(45) (5) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, the solution pH was neutral, the peristaltic pump rotation speed was set to 6 L/h. After two hours of degradation, the dye removal rate of the dye reached 93%, the degradation effect was good.

Example 4

Sponge+Magnetron Sputtering Nickel+Magnetron Sputtering Niobium+Ultrasonic Seeding+BDD

(46) (1) A metal nickel foamed skeleton was deposited on the surface of the sponge foam substrate by using magnetron sputtering, and then the metal niobium was magnetronarily sputtered on the surface of the nickel. The sponge matrix had a pore size of 0.05 mm, the opened cell ratio of 50%, the pores were evenly distributed or randomly distributed, the sponge matrix was a two-dimensional planar sheet-like structure.

(47) (2) The foamed metal substrate (having a size of 3 cm×2 cm×0.3 cm) obtained in the step (1) was placed in a suspension of the nanocrystalline and microcrystalline diamond mixed particles, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh was obtained.

(48) (3) The diamond film was deposited on the foamed metal substrate that was obtained in the step (2) by hot filament chemical vapor deposition. The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 800° C., the hot filament temperature is 2200° C., the deposition pressure is 3.5 kPa, the deposition time is 6 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 10 μm, decreasing in turn toward the core, the core grain size was about 100 nm.

(49) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using the stainless steel electrode as the cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the active blue KN-R with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(50) (5) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the peristaltic pump rotation speed was set to 6 L/h. After two hours of degradation, the color removal rate of the dye reached 90%.

Example 5

Foamed Nickel+Magnetron Sputtering Niobium+Ultrasonic Seeding+Electrostatic Adsorption+BDD

(51) (1) A metal ruthenium foamed skeleton was deposited on the surface of the foamed nickel by using magnetron sputtering. The skeleton had a porosity of 80% a, the pore diameter was 0.05 mm.

(52) (2) The foamed metal substrate (having a size of 3 cm×2 cm×0.3 cm) obtained in the step (1) was placed in a suspension of the nanocrystalline and microcrystalline diamond mixed particles, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh was obtained.

(53) (3) The diamond film was deposited on the foamed metal substrate that was obtained in the step (2) by hot filament chemical vapor deposition. The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 850° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 12 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.4:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 20 μm, decreasing in turn toward the core, the core grain size was about 200 nm.

(54) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using the stainless steel electrode as the cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the active blue KN-R with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(55) (5) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the peristaltic pump rotation speed was set to 6 L/h. After two hours of degradation, the dye removal rate of the dye reached 99%, the degradation effect was good.

Example 6

Foamed Copper+Magnetron Sputtering Titanium+Magnetron Sputtering Niobium+Ultrasonic Seeding+BDD

(56) (1) A layer of metallic titanium was deposited on the surface of the foamed copper by using magnetron sputtering, and a layer of metal niobium was magnetron sputtered in situ. The skeleton had a porosity of 50%, the pore diameter was 0.1 mm.

(57) (2) The metal foam obtained in the step (1) (having a size of 3 cm×2 cm×0.3 cm) was placed in a suspension of the mixed crystal of the nanocrystalline and microcrystalline diamond, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh was obtained.

(58) (3) The diamond film was deposited on the foamed metal substrate that was obtained in the step (2) by hot filament chemical vapor deposition. The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 850° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 6 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 10 μm, decreasing in turn toward the core, the core grain size was about 100 nm.

(59) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using stainless steel electrode as the cathode, the electrolytic solution with a capacity of 1 L after connecting the power source, the inside of the tank was a concentrated solution of the landfill leachate. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(60) (5) The current density during the degradation process was 150 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the rotational speed of the peristaltic pump was set to 6 L/h. After three hours of degradation, the COD degradation rate of landfill leachate reached 95%.

Example 7

Copper Foam+Magnetron Sputtering Niobium+Ultrasonic Seeding+BDD

(61) (1) A layer of metal ruthenium was deposited on the surface of the foamed copper by using magnetron sputtering, a metal niobium foamed skeleton was obtained. The skeleton had a porosity of 90%, the pore diameter was 0.05 mm.

(62) (2) The metal foam obtained in the step (1) (having a size of 3 cm×2 cm×0.3 cm) was placed in a suspension of the mixed crystal of the nanocrystalline and microcrystalline diamond, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton lining having nanocrystalline and microcrystalline diamond particles adsorbed on the surface of the mesh was obtained.

(63) (3) The diamond film was deposited on the foamed metal substrate that was obtained in the step (2) by hot filament chemical vapor deposition. The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 800° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 6 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 10 μm, decreasing in turn toward the core, the core grain size was about 100 nm.

(64) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using the stainless steel electrode as the cathode, the electrolytic solution with a capacity of 1 L after connecting the power source, the inside of the tank was a concentrated solution of the landfill leachate. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(65) (5) The current density during the degradation process was 150 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, and the rotational speed of the peristaltic pump was set to 6 L/h. After three hours of degradation, the COD degradation rate of landfill leachate reached 87%.

Example 8

Copper Foam+Magnetron Sputtering Titanium+Ultrasonic Implant Seed+BDD

(66) (1) A layer of metallic titanium was deposited on the surface of the foamed copper by using magnetron sputtering, a metallic titanium foamed skeleton was obtained. The skeleton has a porosity of 90%, the pore diameter was 0.05 mm.

(67) (2) The metal foam obtained in the step (1) (having a size of 3 cm×2 cm×0.3 cm) is placed in a suspension of nanocrystalline and microcrystalline diamond mixed particles, oscillating in the ultrasonic wave and dispersing uniformly, a foamed skeleton liner with nanocrystalline and microcrystalline diamond particles was obtained.

(68) (3) The diamond film was deposited on the foamed metal substrate that was obtained in the step (2) by hot filament chemical vapor deposition. The deposition process parameters were as follows: the hot wire is 6 mm from the substrate, the substrate temperature is 800° C., the hot wire temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 12 hours, the volumetric flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 was 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode was obtained. The surface layer of the electrode had a grain size of about 20 μm, decreasing in turn toward the core, the core grain size was about 200 nm.

(69) (4) The boron doped diamond electrode prepared in the step (3) was packaged, using the stainless steel electrode as cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the reactive orange X-GN with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(70) (5) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.05 mol/L, using sulfuric acid to regulate the pH of the solution was 11, the peristaltic pump rotation speed was set to 6 L/h.

(71) After two hours of degradation, the dye removal rate of the dye reached 85%.

Example 9

Foam Copper+Ultrasonic Implant Seed+BDD

(72) (1) Using copper foam as a metal skeleton, the skeleton has a porosity of 90% and a pore diameter of 0.05 mm. The metal foam is placed in a suspension of the nanocrystalline and microcrystalline diamond mixed particles, oscillated and dispersed uniformly in the ultrasonic wave, and a foam skeleton lining on which the nanocrystalline and microcrystalline diamond particles are adsorbed on the surface of the mesh is obtained.

(73) (2) The hot metal chemical vapor deposited diamond film was prepared on the foam metal substrate (size 3 cm×2 cm×0.3 cm) obtained in the step (1). The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 850° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 6 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 15 μm, decreasing in turn toward the core, the core grain size was about 100 nm.

(74) (3) The boron doped diamond electrode prepared in the step (2) was packaged, using the stainless steel electrode as cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the reactive orange X-GN with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(75) (4) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.05 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the peristaltic pump rotation speed was set to 6 L/h. After two hours of degradation, the dye removal rate of the dye reached 80%.

Example 10

Sintered Porous Ti+Ultrasonic Implanted Seed Crystal+Electrostatic Adsorption+BDD

(76) (1) Using sintered porous titanium as a metal skeleton, the porosity of the skeleton was 40%. The metal skeleton is placed in a suspension of nanocrystalline and microcrystalline diamond mixed particles, oscillated and dispersed uniformly in an ultrasonic wave, and a foam skeleton lining on which a nanocrystalline and microcrystalline diamond particles are adsorbed on the surface of the mesh is obtained.

(77) (2) The hot metal chemical vapor deposited diamond film was prepared on the foam metal substrate (size 3 cm×2 cm×0.3 cm) obtained in the step (1). The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 800° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 6 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three-dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 10 μm, decreasing in turn toward the core, the core grain size was about 100 nm.

(78) (3) The boron doped diamond electrode prepared in the step (3) was packaged, using the stainless steel electrode as cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the active blue KN-R with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(79) (4) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.05 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the peristaltic pump rotation speed was set to 6 L/h. After two hours of degradation, the dye removal rate of the dye reached 82%.

Example 11

Planar Metal Niobium+Ultrasonic Implant Seed+BDD

(80) (1) A flat metal raft was used as an electrode matrix (size 3 cm×2 cm×0.3 cm). The flat metal ruthenium plate is washed with acetone to remove oil and ultrasonically washed with ethanol, and then placed in a suspension of nanocrystalline and microcrystalline diamond mixed particles, oscillated and dispersed uniformly in the ultrasonic wave, and the surface thereof is adsorbed with nanocrystals and micrometers.

(81) (2) The hot metal chemical vapor deposited diamond film was prepared on the flat metal niobium substrate obtained in the step (1). The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 850° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 6 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a diamond electrode doped with boron on flat niobium plate is obtained. The surface layer of the electrode had a grain size of about 10 μm.

(82) (3) The boron doped diamond electrode prepared in the step (2) was packaged, using the stainless steel electrode as cathode, the electrolytic cell with capacity of 1 L after connecting the power supply, the dye was the reactive orange X-GN with concentration of 100 mg/L. The apparatus used for treating organic sewage was shown in the attached drawing (1).

(83) (4) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.05 mol/L, using sulfuric acid to regulate the pH of the solution was 3, the peristaltic pump rotation speed was set to 6 L/h. After two hours of degradation, the dye removal rate of the dye reached 75%.

Example 12

Foam Niobium+Ultrasonic Implant Seed+BDD

(84) (1) Using foam enamel as a metal skeleton, the skeleton has a porosity of 90% and a pore diameter of 0.05 mm. The metal foam is placed in a suspension of the nanocrystalline and microcrystalline diamond mixed particles, oscillated and dispersed uniformly in the ultrasonic wave, and a foam skeleton lining on which the nanocrystalline and microcrystalline diamond particles are adsorbed on the surface of the mesh is obtained.

(85) (2) The hot metal chemical vapor deposited diamond film was prepared on the foam niobium substrate obtained in the step (1). The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 850° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the deposition time is 10 hours, the volume flow ratio of B.sub.2H.sub.6/CH.sub.4/H.sub.2 is 0.2:1:99; a three dimensional space network porous boron doped diamond electrode is obtained. The surface layer of the electrode had a grain size of about 20 μm, decreasing in turn toward the core, the core grain size was about 400 nm.

(86) (3) The electrochemical detection of glucose by pure BDD electrode showed that the detection sensitivity of pure BDD electrode was extremely low (about 10 μA mM.sup.−1cm.sup.−2), and the detection limit is 0.5 μM.

(87) (4) Electrochemical detection of glucose by foamed copper composite BDD electrode, time current test results surface foam copper composite BDD electrode sensitivity up to 1642.20 μAmM.sup.−1cm.sup.−2, and the detection limit is 0.1 μM, the electrode can detect glucose concentration range of 10 μM-25.5 mM, moreover, the stability of the composite electrode is high, and in the continuous test for up to one month, the current response value still has 90.6% of the initial electrode.

Example 13

Planar Type (Board)

(88) (1) Cleaning the planar niobium substrate;

(89) (2) Depositing a layer of metal chromium having a thickness of 500 nm on the surface of the flat plate by magnetron sputtering;

(90) (3) The chromium-modified plate crucible was placed in a suspension of nanocrystalline and microcrystalline diamond mixed particles, shaken in an ultrasonic wave for 30 min, and uniformly dispersed to obtain a ruthenium matrix having nanocrystalline and microcrystalline diamond particles adsorbed on the surface.

(91) (4) The boron-doped diamond film was deposited by hot-wire CVD. The deposition process parameters are as follows: hot wire distance is 6 mm, deposition temperature is 700-750° C., hot wire temperature is 2200° C., deposition pressure is 3 kPa, gas ratio (CH.sub.4:H.sub.2:B.sub.2H.sub.6) (sccm) is 3:97:0.3, which is controlled the deposition time to obtain a diamond film thickness of 20 μm;

(92) (5) The surface of the boron doped diamond prepared in the step (4) is deposited by a magnetron sputtering deposition method, and the sputtering parameters are a sputtering current of 400 mA, an argon flow rate of 10 sccm, a sputtering pressure of 0.4 Pa, and a sputtering time of 10 min. The thickness of the nickel layer is 500 nm;

(93) (6) The sample prepared according to step (5) is placed in a tube furnace with a vacuum device, the catalytic temperature is set to 700° C., the catalytic etching gas is nitrogen, the catalytic etching pressure is 1 atm, and the catalytic etching time is 2 h;

(94) (7) Boron doped diamond electrode material is obtained with a high specific surface area by furnace cooling.

(95) The SEM morphology of the diamond film at different catalytic etching temperatures is shown in FIG. 2a-2h. As can be seen from FIG. 2a-2d, the nickel film produces a small amount of agglomeration at 700° C., but still completely covers the diamond surface; When the temperature rises to 800° C., the nickel film further agglomerates and grows, and the nickel strips are connected to each other to form a metal nickel mesh covering the diamond film; When the temperature rises to 900° C., the nickel agglomeration is serious, There are only a few nickel bars left on the diamond surface. A small amount of nickel strips, from the surface exposed after the nickel film is agglomerated, which can be seen that the original morphology of the diamond has changed significantly. FIG. 2e-2h show the SEM morphology of the diamond film after nickel treatment with dilute nitric acid. It can be seen from the figure that as the temperature increases, the diamond film is etched more seriously. When the temperature is 700° C., the diamond film is partially etched. Some areas with severe etching have many uneven bumps, while the rest still retain the original diamond morphology. When the temperature is 800° C., the etching degree is intensified and there are no large pieces of diamond exist on the surface. All areas are etched to grow protrusions with different diameter ratios; When the temperature rises to 900° C., the surface diamond is completely etched, and the protrusion formed at low temperature becomes another foam-like porous structure.

Example 14

Planar Type (Plate)

(96) (1) Cleaning the tungsten sheet;

(97) (2) The tungsten sheet is placed in a suspension of nanocrystalline and microcrystalline diamond mixed particles, shaken in an ultrasonic wave for 30 min, and uniformly dispersed to obtain a ruthenium matrix having nanocrystalline and microcrystalline diamond particles adsorbed on the surface.

(98) (3) The boron-doped diamond film was deposited by hot filament CVD. The deposition process parameters were as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 700-750° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the volume flow ratio of CH.sub.4:H.sub.2:B.sub.2H.sub.6 is 3:97:03; the thickness of the diamond film is 25 μm by controlling the deposition time;

(99) (4) Metal nickel layer was deposited on the surface of boron doped diamond prepared in step (3) by magnetron sputtering method. The specific sputtering parameters were 400 mA of sputtering current, 10 sccm of argon flow, 0.4 Pa of sputtering pressure, and sputtering time were 15 s, 30 s and 60 s, respectively.

(100) (5) Put the sample obtained in step (4) into the tube furnace with vacuum equipments, the catalyst temperature is 800° C., catalytic etching gas is CH.sub.4 (1.5 sccm) and H.sub.2 (28.5 sccm), catalytic etching pressure is 10 kPa, and catalytic etching time is 40 min.

(101) (6) Boron-doped diamond/carbon nanotube electrode materials with high specific surface area are obtained with furnace cooling, as shown in FIG. 2a-2h.

(102) In FIGS. 3a-3f are the SEM morphological images and their magnifications of BDD/CNT (carbon nanotubes) composite films catalyzed after different sputtering time of Ni. The surface morphology of films before and after Ni catalytic growth were compared. After the catalytic growth of Ni film, the typical diamond morphology could not be seen on the surface of BDD, the surface of BDD was covered with a thick layer of carbon nanotubes. Further comparison of surface morphology of BDD/CNT composite films catalyzed by different sputtering time showed that the thickness of sputtered Ni had a great influence on the catalytic growth of carbon nanotubes. When the sputtering Ni films took a relatively short time (15 s), the electrode surface was covered with a layer of tubular catalytic products, which were evenly distributed, interlaced and superimposed on the electrode surface, and the film surface morphology was completely changed, accompanied by the agglomeration of Ni nanoparticles (FIG. 3a-3b; When the sputtering time of Ni film was 30 s, the coverage of carbon nanotubes on the surface of BDD/CNT composite film decreased, and initial BDD morphology began to appear in some regions, and the length of tubular catalytic products increased (FIG. 3c-3d); When the sputtering time of Ni film was 60 s, the carbon nanotube coverage on the surface of BDD/CNT composite film was further reduced, the initial BDD morphology of most areas was exposed, and the length of the catalytic growth of carbon nanotubes was further increased (FIG. 3e-3f).

Example 15

Planar Type (Plate)

(103) (1) Cleaning the niobium wafer;

(104) (2) Put niobium in nanocrystalline and microcrystalline diamond particle suspensions for ultrasonic oscillation of 30 min, to get niobium substrates with nanocrystalline and microcrystalline diamond grains absorbed on the surface;

(105) (3) Using hot filament CVD technique to deposit boron doped diamond film, the deposition process parameters are as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 700-750° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the volume flow ratio of CH.sub.4:H.sub.2:B.sub.2H.sub.6 is 3:97:03; deposition time is 4 h;

(106) (4) Metal nickel layer was deposited on the surface of the boron doped diamond films obtained in step (3) by magnetron sputtering deposition method. Spraying parameters are sputtering current of 400 mA, the argon gas flow of 10 sccm, sputtering pressure of 0.4 Pa, sputtering time of 60 s;

(107) (5) Samples obtained in step (4) was put in a tube furnace with vacuum equipment. The catalyst temperature is 700° C., the catalytic etching gas CH.sub.4 and H.sub.2, methane concentration ((CH.sub.4)/(CH.sub.4+H.sub.2)) are 0.5%, 5%, 10%, catalytic etching pressure is 10 kPa, and catalytic etching time is 40 min.

(108) (6) With furnace cooling to obtain boron doped diamond electrode materials/carbon nanotubes of high specific surface area, as shown in FIG. 3a-3h.

(109) FIG. 4a-4c are the SEM morphologies of boron doped diamond/carbon nanotube composite membranes catalyzed and grew under different concentrations of methane. You can see from the picture that under different concentrations of methane, the different degrees of changes have taken place on the original diamond surface. With the increase of methane concentration, the change was more obvious and the number of carbon nanotubes was also increased. FIG. 4a was the surface morphology of diamond catalyzed and grew under methane of low concentration (0.5%). Nickel on the surface of the diamond film produced a certain degree of reunion at high temperature, formed the reunion of a small amount of dispersed particles, but due to methane concentrations did not reach the demand to generate the nanotubes, the surface did not find a tubular shape catalytic product generation, you can see from figure that crystal grain faceted of the film was clear and still maintained the original diamond surface morphology. When methane concentrations were up to 5%, some changes have taken place in thin film surface, diamond, though still maintained the original particle morphology, but the edge facet has become blurred. It can be seen from the amplification in FIG. 4b that diamond surface has been covered totally by short carbon nanotubes about 20 nm in diameter. As catalytic methane concentrations increased to 10% (FIG. 4c), carbon nanotube growth further, mutual crisscross stacking adhere to the surface of diamond, and as a result of the carbon nanotubes' coverage, the original diamond thin film surface morphology has completely changed.

(110) FIG. 4d-4f are the Guassian multi-peak fitting maps of Raman spectra of samples under different catalytic concentrations and its specific parameter values. It can be seen from the picture that with the increase of catalytic concentration, Raman spectra have identical changes. When catalytic methane concentration was 0.5%, there are four main characteristic peaks appeared at 1332 cm.sup.−1, 1350 cm.sup.−1, 1580 cm.sup.−1, 2700 cm.sup.−1, respectively. The highest peak at 1332 cm.sup.−1 was diamond phase characteristic peak (Dia peak), and two low “steamed bread peak” appeared at 1580 cm.sup.−1 and 1350 cm.sup.−1 was graphite peak caused by the sp.sup.2 phase, commonly referred to as graphite D peak, G peak, respectively. The small peak appears at 2700 cm.sup.−1 of high frequency peak was the second-order characteristic peak of graphite phase, known as the 2D peak. The Raman spectra show that samples catalyzed and grew under low concentrations of methane are mainly composed of diamond phase and sp.sup.2 phase content like graphite was small. When the catalytic methane concentrations continue to rise, the curves of samples under 5% and 10% have obvious changes comparing to that of samples under low catalytic concentrations. Raman spectra of samples catalyzed under high concentrations appeared two sharp sp.sup.2 characteristic peaks at 1350 cm.sup.−1 (D peak) and 1600 cm.sup.−1 (G peak) at 1350 cm.sup.−1, show that samples contain a large amount of graphite phase, integrated SEM results, the graphite phase was carbon nanotubes form. In many studies, the ratio of D peak and G peak (I.sub.D/I.sub.G) is generally used to measure the graphitization state of disorderly carbon materials, the smaller intensity ratio means the higher quality of the graphite in samples. In this implementation, the I.sub.D/I.sub.G values of samples catalyzed under methane concentrations of 5% and 10% were measured as 0.93 and 0.89, respectively. The results show that with the increase of catalytic concentration, the generated composite membrane has a better graphite structure. In addition, there were another four small peaks appeared in the Raman spectra of two samples catalyzed under high catalytic concentrations: the peak at 1332 cm.sup.−1 was low and half high width value was big, showed that the diamond phase in the sample was little; graphite G peaks appeared at 1600 cm.sup.−1 and 1580 cm.sup.−1, the appearance of multi-peak structure was because when generating carbon nanotubes, graphene will curl into a cylindrical tube, which will lead to the symmetry destruction of graphite tangential Raman vibration and quantum confinement effect of phonon wave loss along the circumferential direction of carbon nanotubes, while large diameter multi-walled carbon nanotubes have continuous diameter distribution, the asymmetric characteristics of G band is weak, so the multi-walled carbon nanotubes will not appear 5-6 G peak splittings like single-walled carbon nanotubes, and only one Raman spectrum peak appears near graphite frequency of 1580 cm.sup.−1. In addition, peaks at high frequencies of 2700 cm.sup.−1 (2D) and 2900 cm.sup.−1 (D+G) can further prove the presence of carbon nanotubes in samples.

Example 16

Planar Spiral Type

(111) (1) Cleaning planar spiral niobium substrates;

(112) (2) Depositing a thickness of 500 nm metal tungsten layer on the surface of spiral niobium;

(113) (3) Put niobium in nanocrystalline and microcrystallinemicrocrystalline diamond particle suspensions for ultrasonic oscillation of 30 min, to get niobium substrates with nanocrystalline and microcrystalline diamond grains absorbed on the surface;

(114) (4) Using hot filament CVD technique to deposit boron doped diamond film, the deposition process parameters are as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 700-750° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the volume flow ratio of CH.sub.4:H.sub.2:B.sub.2H.sub.6 is 3:97:03; diamond film thickness is 50 μm controlled by deposition time;

(115) (5) Metal cobalt layer was deposited on the surface of the boron doped diamond films obtained in step (4) by magnetron sputtering deposition method. The sputtering current is 450 mA, the argon gas flow is 10 sccm, sputtering pressure is 0.4 Pa, sputtering time is 10 min and the cobalt layer thickness is 1 μm;

(116) (6) Samples obtained in step (5) was put in a tube furnace with vacuum equipment. The catalyst temperature is 700° C., the catalytic etching gas is H.sub.2, catalytic etching pressure is 1 atmosphere, and catalytic etching time is 3 h. The electrode materials were distributed evenly over the surface of holes of 9-12 μm.

(117) (7) With furnace cooling to obtain boron doped diamond electrode materials of high specific surface area, as shown in FIG. 3a-3h.

(118) Encapsulating boron doped diamond electrodes prepared by the above steps, using stainless steel electrode as cathode, the electrolytic solution with a capacity of 1 L after connecting the power source, the inside of the tank was a concentrated solution of the landfill leachate. The current density during the degradation process was 150 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, and the rotational speed of the peristaltic pump was set to 6 L/h. After three hours of degradation, the COD degradation rate of landfill leachate reached 87%.

Example 17

Macroporous Foam Type

(119) (1) Cleaning copper foam substrates whose diameter is 0.1 mm;

(120) (2) Depositing a thickness of 500 nm metal molybdenum layer on the surface of copper foam;

(121) (3) Put copper foam modified by molybdenum in nanocrystalline and microcrystalline diamond particle suspensions for ultrasonic oscillation of 30 min, to get copper foam substrates with nanocrystalline and microcrystalline diamond grains absorbed on the surface;

(122) (4) Using hot filament CVD technique to deposit boron doped diamond film, the deposition process parameters are as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 700-750° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the volume flow ratio of CH.sub.4:H.sub.2:B.sub.2H.sub.6 is 3:97:03; diamond film thickness is 50 μm controlled by deposition time;

(123) (5) Metal nickel layer was deposited on the surface of the boron doped diamond films obtained in step (4) by magnetron sputtering deposition method. The sputtering current is 450 mA, the argon gas flow is 10 sccm, sputtering pressure is 0.4 Pa, sputtering time is 20 min and the nickel layer thickness is 1 μm;

(124) (6) Samples obtained in step (5) was put in a tube furnace with vacuum equipment. The catalyst temperature is 900° C., the catalytic etching gas is N.sub.2, catalytic etching pressure is 1 atmosphere, and catalytic etching time is 3 h;

(125) (7) With furnace cooling to obtain boron doped diamond electrode materials of high specific surface area, the electrode materials were distributed evenly over the surface of holes above 15 μm.

(126) Encapsulating boron doped diamond electrodes prepared by the above steps, using stainless steel electrode as cathode. After connecting the power supply, it was placed in an electrolytic cell having a capacity of 1 L, and the dye was reactive orange X-GN having a concentration of 100 mg/L. The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.1 mol/L, using sulfuric acid to regulate the pH of the solution was 3, and the rotational speed of the peristaltic pump was set to 6 L/h. After two hours of degradation, the color removal rate of the dye reached 99%, the basic degradation was complete.

Example 18

Foam Porous Type

(127) ((1) Selecting copper foam with a pore size of 0.1 mm, cleaning the copper foam skeleton;

(128) (2) Depositing a layer of metal tungsten having a thickness of 500 nm on the surface of the foamed copper by an evaporation method;

(129) (3) Put copper foam modified by tungsten in a suspensions of nanocrystalline and microcrystalline diamond mixed particles, shaken in an ultrasonic wave for 30 min, uniformly dispersed, obtained a copper foam with nanocrystalline and microcrystalline diamond particles adsorbed on the surface;

(130) (4) Using hot filament CVD technique to deposit boron doped diamond film, the deposition process parameters are as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 700-750° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the volume flow ratio of CH.sub.4:H.sub.2:B.sub.2H.sub.6 is 3:97:03; diamond film thickness is 50 μm controlled by deposition time;

(131) (5) Metal nickel layer was deposited on the surface of boron doped diamond prepared in step (4) by magnetron sputtering deposition method, spraying parameters are sputtering current of 450 mA, the argon gas flow of 10 sccm, sputtering pressure of 0.4 Pa, sputtering time is 20 min, the nickel layer thickness is 1 μm;

(132) (6) The sample prepared in the step (5) is placed in a tube furnace with a vacuum device, the catalytic temperature is set to 900° C., the catalytic etching gas is nitrogen, the catalytic etching pressure is 1 atm, and the catalytic etching time is 3 h;

(133) (7) With furnace cooling to obtain boron doped diamond electrode materials of high specific surface area. The electrode materials were distributed evenly over the surface of holes above 15 μm.

(134) The prepared boron doped diamond electrode was tested for glucose on the CHI 660E electrochemical workstation, the time current method test results show that the detection sensitivity of the composite electrode can reach 2.5 mAmM.sup.−1cm.sup.−2, the detection limit is 0.05 μM, the detectable glucose concentration range from 0.1 μM-10 mM, the stability of the composite electrode is high, in the current detection process for one month, the detection sensitivity can still maintain accuracy of more than 90%.

Example 19

Nitrogen Doped Diamond Foam Electrode

(135) (1) Selecting copper foam with a pore size of 0.3 mm, removing the metal oxide on the surface of the copper foam with 1 vol. % HCl, then removing the surface oil with acetone;

(136) (2) A metal chromium film as an intermediate transition layer having a thickness of 50 nm is deposited on the surface of the copper foam by a magnetron sputtering method;

(137) (3) Put copper foam modified by chromium in a suspensions of nanocrystalline and microcrystalline diamond mixed particles, shaken in an ultrasonic wave for 30 min, uniformly dispersed, obtained a copper foam with nanocrystalline and microcrystalline diamond particles adsorbed on the surface;

(138) (4) Using hot filament CVD technique to deposit boron doped diamond film, the deposition process parameters are as follows: the hot filament is 6 mm from the substrate, the substrate temperature is 700-750° C., the hot filament temperature is 2200° C., the deposition pressure is 3 kPa, the volume flow ratio of CH.sub.4:H.sub.2:B.sub.2H.sub.6 is 3:97:03; the nitrogen doped diamond foamed electrode of a three-dimensional network is obtained. The thickness of the nitrogen doped diamond film is 50 μm.

(139) (5) The boron doped diamond electrode prepared in the step (4) is packaged, using stainless steel electrode as cathode. After connecting the power supply, it was placed in an electrolytic cell having a capacity of 1 L, and the dye was reactive orange X-GN having a concentration of 100 mg/L. The apparatus used for treating organic sewage is shown in the attached drawing (1).

(140) (6) The current density during the degradation process was 100 mA/cm.sup.2, the supporting electrolyte was sodium sulfate, the concentration was 0.05 mol/L, using sulfuric acid to regulate the pH of the solution was 3, and the rotational speed of the peristaltic pump was set to 6 L/h. After three hours of degradation, the color removal rate of the dye reached 86%.