PHOTOCATALYST AND APPLICATION THEREOF IN ENVIRONMENTALLY FRIENDLY PHOTOCATALYTIC TREATMENT OF POWER BATTERY

Abstract

Disclosed are a photocatalyst and application thereof in environmentally friendly photocatalytic treatment of a power battery. The photocatalyst is obtained by loading Ag-TaON on a hollow glass microsphere, wherein a mass ratio of the Ag-TaON to the hollow glass microsphere is 1: 5 to 10. According to the invention, the Ag-TaON and the hollow glass microsphere are compounded, the hollow glass microsphere has better light permeability, which avoids mutual shielding between catalysts, such that the photocatalyst filled in a reactor is fully excited, which is capable of effectively improving a light utilization rate, thus improving the catalytic conversion efficiency of the photocatalyst.

Claims

1. A photocatalyst, wherein the photocatalyst is obtained by loading Ag-TaON on a hollow glass microsphere; and a mass ratio of the Ag-TaON to the hollow glass microsphere is 1: (5 to 10): wherein the photocatalyst is prepared by the following steps of: (1) grinding TaON into powder, dispersing the powder in a solvent, adding a soluble silver salt, stirring, irradiating, centrifuging and washing to obtain a Ag-TaON catalyst; and (2) dispersing the Ag-TaON catalyst in a sodium tripolyphosphate solution, adding the hollow glass microsphere, stirring and sintering to obtain the photocatalyst with Ag-TaON loaded on the hollow glass microsphere.

2. The photocatalyst of claim 1, wherein the hollow glass microsphere has a particle size ranging from 10 .Math.m to 10 mm.

3. (canceled)

4. The photocatalyst of claim 1, wherein in step (1), the solvent is water and methanol; a mass ratio of the TaON to the water to the methanol is 1: (20 to 60): (15 to 40); and the soluble silver salt is a AgNO.sub.3 solution.

5. The photocaialyst of claim 1, wherein in step (2), the sintering is carried out at a temperature of 200° C. to 300° C. in a nitrogen atmosphere, and lasts for 1 hour to 2 hours.

6. The photocatalyst of claim 1, wherein the TaON is prepared by the following steps: (1) pretreating a tantalum foil; (2) cooling, introducing an inert gas, then introducing reaction gas A, raising a temperature, keeping the temperature and reacting to obtain Ta.sub.2O.sub.5; and (3) cooling, introducing an inert gas, then introducing reaction gas B, raising the temperature, keeping the temperature and reacting to obtain TaON, wherein in step (2), the reaction gas A is a mixed gas of O.sub.2 and N.sub.2; and the reaction gas B in step (3) is a mixed gas of NH.sub.3 and N.sub.2.

7. The photocatalyst of claim 1 wherein the pretreating of step (1) comprises pushing a corundum porcelain boat containing the tantalum foil into a middle heating section of a tube furnace, sealing with a flange, and introducing an inert gas at a flow rate of 2 mL.Math.min.sup.-1 to 30 mL.Math.min.sup.-1 for 20 minutes to 120 minutes at ambient temperature; and then, switching to another gas channel to introduce a pretreatment gas at a flow rate of 2 mL.Math.min.sup.-1 to 30 mL.Math.min.sup.-1, then raising the temperature to 250° C. to 350° C. at a rate of 2° C..Math.min.sup.-1 to 8° C..Math.min.sup.-1, and keeping the temperature for 30 minutes to 150 minutes, wherein the pretreatment gas is a mixed gas of H.sub.2 and N.sub.2.

8. The photocatalyst of claim 5, wherein in step (2) and step (3), the inert gas is at least one selected from the group consisting of pure N.sub.2, Ar, and He.

9. An environmentally friendly photocatalytic treatment method of a power battery, comprising: (1) disassembling and pyrolyzing a waste lithium battery to obtain a gas mixed with an electrolyte; and (2) introducing the gas mixed with the electrolyte into a cleaning liquid, then introducing the gas mixed with the electrolyte into a reactor filled with the photocatalyst according to claim 1, and irradiating with a light source for photocatalysis to degrade the electrolyte into CO.sub.2 and H.sub.2O.

10. The environmentally friendly photocatalytic treatment method of the power battery of claim 9, wherein the cleaning liquid is at least one selected from the group consisting of NaOH, Ca(OH).sub.2, and KOH.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0050] FIG. 1 is an SEM graph of Ag-TaON powder in Embodiment 2 of the present invention;

[0051] FIG. 2 is an SEM graph of a photocatalyst prepared in Embodiment 2 of the present invention; and

[0052] FIG. 3 is an XRD graph of the Ag-TaON powder in Embodiment 2 of the present invention.

DETAILED DESCRIPTION

[0053] In order to make the technical solutions of the present invention clearer to those skilled in the art, the following embodiments are listed for explanation. It should be noted that the following embodiments do not limit the scope of protection claimed by the present invention.

[0054] Unless otherwise specified, the raw materials, reagents or devices used in the following embodiments can be obtained from conventional commercial sources or by existing known methods.

Embodiment 1

[0055] A photocatalyst was obtained by loading Ag-TaON on a hollow glass microsphere; and a mass ratio of the Ag-TaON to the hollow glass microsphere was 1: 5.

[0056] A preparation method of a power battery photocatalyst includes steps of: [0057] (1) pushing a corundum porcelain boat containing a tantalum foil into a middle heating section of a tube furnace, sealing with a flange, introducing pure N.sub.2 at a flow rate of 2 mL.Math.min.sup.-1 for 20 minutes at ambient temperature, switching to another gas channel to introduce a mixed gas of H.sub.2 and N.sub.2 at a flow rate of 2 mL.Math.min.sup.-1, the H.sub.2 having a concentration of 5%, and meanwhile, starting a temperature control program to raise the temperature to 250° C. at a rate of 2° C..Math.min.sup.-1, and keeping the temperature for 30 minutes; [0058] (2) reducing the temperature to ambient temperature, switching to another gas channel to introduce pure N.sub.2 at a flow rate of 2 mL.Math.min.sup.-1 for 20 minutes, then switching to another gas channel to introduce a mixed gas of O.sub.2 and N.sub.2 at a flow rate of 2 mL.Math.min.sup.-1, the O.sub.2 having a concentration of 5%, and meanwhile, starting the temperature control program to raise the temperature to 500° C. at a rate of 2° C..Math.min.sup.-1, and keeping the temperature for 30 minutes to obtain Ta.sub.2O.sub.5; [0059] (3) reducing the temperature to ambient temperature, switching to another gas channel to introduce pure N.sub.2 at a flow rate of 2 mL.Math.min.sup.-1 for 20 minutes, then switching to another gas channel to introduce a mixed gas of NH.sub.3 and N.sub.2 at a flow rate of 2 mL.Math.min.sup.-1, the NH.sub.3 having a concentration of 5%, and meanwhile, starting the temperature control program to raise the temperature to 800° C. at a rate of 2° C..Math.min.sup.-1, and keeping the temperature for 180 minutes to obtain TaON; [0060] (4) reducing the temperature to ambient temperature, taking the TaON out, grinding the TaON into powder, adding magnetons according to a proportion of 1 g: 20 mL: 15 mL (TaON: water: methanol) to form a disperse system under vigorously magnetic stirring (a speed of revolution of 800 r/min), placing the disperse system in nitrogen atmosphere, then adding a AgNO.sub.3 solution with a concentration of 0.5 mol.Math.L.sup.-1 according to the load of 0.5%, and then stirring for 5 minutes, irradiating the mixture with a high-pressure mercury lamp for 10 minutes, centrifuging and washing the mixture to obtain a Ag-TaON catalyst; and [0061] (5) dispersing the Ag-TaON catalyst in a sodium tripolyphosphate solution with a concentration of 0.1 mol.Math.L.sup.-1, adding 200 mesh hollow glass microsphere according to a weight ratio of 1:5 (Ag-TaON: hollow glass microsphere), stirring the mixture (a speed of revolution of 400 r/min) for 20 minutes, drying the mixture, and then sintering the same at 200° C. for 1 hour under nitrogen atmosphere to obtain the photocatalyst loaded on the surfaces of the hollow glass microsphere.

[0062] An environmentally friendly photocatalytic treatment method of a power battery includes steps of: [0063] (1) disassembling and pyrolyzing a waste lithium battery to obtain a gas mixed with an electrolyte; and [0064] (2) introducing the gas mixed with the electrolyte into a NaOH solution with a concentration of 0.1 mol.Math.L.sup.-1, then introducing the gas mixed with the electrolyte into a reactor filled with the photocatalyst, and irradiating with an ultraviolet lamp for photocatalysis to degrade the electrolyte to obtain CO.sub.2 and H.sub.2O.

Embodiment 2

[0065] A photocatalyst was obtained by loading Ag-TaON on a hollow glass microsphere; and a mass ratio of the Ag-TaON to the hollow glass microsphere was 1: 8.

[0066] A preparation method of a photocatalyst includes steps of: [0067] (1) pushing a corundum porcelain boat containing a tantalum foil into a middle heating section of a tube furnace, sealing with a flange, introducing pure Ar at a flow rate of 15 mL.Math.min.sup.-1 for 70 minutes at ambient temperature, switching to another gas channel to introduce a mixed gas of H.sub.2 and N.sub.2 at a flow rate of 15 mL.Math.min.sup.-1, the H.sub.2 having a concentration of 8%, and meanwhile, starting a temperature control program to raise the temperature to 300° C. at a rate of 5° C..Math.min.sup.-1, and keeping the temperature for 90 minutes; [0068] (2) reducing the temperature to ambient temperature, switching to another gas channel to introduce pure Ar at a flow rate of 15 mL.Math.min.sup.-1 within 70 minutes, then switching to another gas channel to introduce a mixed gas of O.sub.2 and N.sub.2 at a flow rate of 15 mL.Math.min.sup.-1, the O.sub.2 having a concentration of 8%, and meanwhile, starting the temperature control program to raise the temperature to 550° C. at a rate of 5° C..Math.min.sup.-1, and keeping the temperature for 90 minutes to obtain Ta.sub.2O.sub.5; [0069] (3) reducing the temperature to ambient temperature, switching to another gas channel to introduce pure Ar at a flow rate of 15 mL.Math.min.sup.-1 within 70 minutes, then switching to another gas channel to introduce a mixed gas of NH.sub.3 and N.sub.2 at a flow rate of 15 mL.Math.min.sup.-1, the NH.sub.3 having a concentration of 8%, and meanwhile, starting the temperature control program to raise the temperature to 850° C. at a rate of 5° C..Math.min.sup.-1, and keeping the temperature for 240 minutes to obtain TaON; [0070] (4) reducing the temperature to ambient temperature, taking the TaON out, grinding the TaON into powder, adding magnetons according to a proportion of 1 g: 40 mL: 25 mL (TaON: water: methanol) to form a disperse system under vigorously magnetic stirring (a speed of revolution of 1,200 r/min), placing the disperse system in nitrogen atmosphere, then adding AgNO.sub.3 solution with a concentration of 0.8 mol.Math.L.sup.-1 according to the load of 0.7%, and then stirring for 5 minutes, irradiating the mixture with a high-pressure mercury lamp for 20 minutes, centrifuging and washing the mixture to obtain a Ag-TaON catalyst; and [0071] (5) dispersing the Ag-TaON catalyst in a sodium tripolyphosphate solution with a concentration of 0.5 mol.Math.L.sup.-1, adding 300 mesh hollow glass microsphere according to a weight ratio of 1:8 (Ag-TaON: hollow glass microsphere), stirring the mixture (a speed of revolution of 600 r/min) for 40 minutes, drying the mixture, and then sintering the same at 250° C. for 1.5 hours under nitrogen atmosphere to obtain the power battery photocatalyst loaded on the hollow glass microsphere.

[0072] An environmentally friendly photocatalytic treatment method of a power battery includes steps of: [0073] (1) disassembling and pyrolyzing a waste lithium battery to obtain a gas mixed with an electrolyte; and [0074] (2) introducing the gas mixed with the electrolyte into a NaOH solution with a concentration of 0.2 mol.Math.L.sup.-1, then introducing the gas mixed with the electrolyte into a reactor filled with the photocatalyst, and irradiating with an ultraviolet lamp for photocatalysis to degrade the electrolyte to obtain CO.sub.2 and H.sub.2O.

Embodiment 3

[0075] A photocatalyst was obtained by loading Ag-TaON on a hollow glass microsphere; and a mass ratio of the Ag-TaON to the hollow glass microsphere was 1: 8.

[0076] A preparation method of a photocatalyst includes steps of: [0077] (1) pushing a corundum porcelain boat containing a tantalum foil into a middle heating section of a tube furnace, sealing with a flange, introducing pure Ar at a flow rate of 15 mL.Math.min-1 for 70 minutes at ambient temperature, switching to another gas channel to introduce a mixed gas of H2 and N2 at a flow rate of 15 mL.Math.min-1, the H2 having a concentration of 8%, and meanwhile, starting a temperature control program to raise the temperature to 300° C. at a rate of 5° C. • min-1, and keeping the temperature for 90 minutes; [0078] (2) reducing the temperature to ambient temperature, switching to another gas channel to introduce pure Ar at a flow rate of 15 mL.Math.min-1 within 70 minutes, then switching to another gas channel to introduce a mixed gas of O2 and N2 at a flow rate of 15 mL.Math.min-1, the O2 having a concentration of 8%, and meanwhile, starting the temperature control program to raise the temperature to 550° C. at a rate of 5° C. • min-1, and keeping the temperature for 90 minutes to obtain Ta2O5; [0079] (3) reducing the temperature to ambient temperature, switching to another gas channel to introduce pure Ar at a flow rate of 15 mL.Math.min-1 within 70 minutes, then switching to another gas channel to introduce a mixed gas of NH.sub.3 and N.sub.2 at a flow rate of 15 mL.Math.min-1, the NH3 having a concentration of 8%, and meanwhile, starting the temperature control program to raise the temperature to 850° C. at a rate of 5° C. • min-1, and keeping the temperature for 240 minutes to obtain TaON; [0080] (4) reducing the temperature to ambient temperature, taking the TaON out, grinding the TaON into powder, adding magnetons according to a proportion of 1 g: 40 mL: 25 mL (TaON: water: methanol) to form a disperse system under vigorously magnetic stirring (a speed of revolution of 1,200 r/min), placing the disperse system in nitrogen atmosphere, then adding AgNO3 solution with a concentration of 0.8 mol.Math.L-1 according to the load of 0.7%, and then stirring for 5 minutes, irradiating the mixture with a high-pressure mercury lamp for 20 minutes, centrifuging and washing the mixture to obtain a Ag-TaON catalyst; and [0081] (5) dispersing the Ag-TaON catalyst in a sodium tripolyphosphate solution with a concentration 0.5 mol.Math.L-1, adding 300 mesh hollow glass microsphere according to a weight ratio of 1:8 (Ag-TaON: hollow glass microsphere), stirring the mixture (a speed of revolution of 600 r/min) for 40 minutes, drying the mixture, and then sintering the same at 250° C. for 1.5 hours under nitrogen atmosphere to obtain the power battery photocatalyst loaded on the surfaces of the hollow glass microsphere.

[0082] An environmentally friendly photocatalytic treatment method of a power battery includes steps of: [0083] (1) disassembling and pyrolyzing a waste lithium battery to obtain a gas mixed with an electrolyte; and [0084] (2) introducing the gas mixed with the electrolyte into a NaOH solution with a concentration of 0.2 mol.Math.L-1, then introducing the gas mixed with the electrolyte into a reactor filled with the photocatalyst, and irradiating with an ultraviolet lamp for photocatalysis to degrade the electrolyte to obtain CO2 and H2O.

Comparative Example 1

[0085] A method for catalyzing an electrolyte of a TaON catalyst includes steps of: [0086] (1) placing Ta.sub.2O.sub.5 in a tube furnace, keeping the temperature at 800° C. for 4 hours in an ammonia atmosphere to obtain TaON, and grinding the TaON into powder to obtain a TaON catalyst; and [0087] (2) adding the TaON and a hollow glass microsphere into a sodium tripolyphosphate solution, stirring, dispersing and drying the mixture, and sintering the mixture at 200° C., and using the obtained catalyst for photocatalytic degradation of the electrolyte in a quartz reactor.

Comparative Example 2

[0088] A method for catalyzing an electrolyte of a Ag-TaON catalyst includes steps of: [0089] (1) placing Ta.sub.2O.sub.5 in a tube furnace, keeping the temperature at 800° C. for 4 hours in an ammonia atmosphere to obtain TaON, grinding the TaON into powder, adding the power into a silver nitrate solution with a load of 0.7%, and reducing with sodium borohydride to obtain Ag-TaON; and [0090] (2) adding the Ag-TaON and a hollow glass microsphere into a sodium tripolyphosphate solution, stirring, dispersing and drying the mixture, and sintering the mixture at 200° C., and using the obtained catalyst for photocatalytic degradation of the electrolyte in a quartz reactor.

Comparison of Degradation Effects

[0091] The products obtained by carrying out photodegradation of electrolyte according to Embodiment 2 and Comparative Examples 1 and 2 were detected by gas chromatography respectively. The yield results are shown in FIG. 1. It can be seen from Table 1 that the catalyst in Comparative Example 1 has no Ag, and the electrolyte conversion rate is 73.2%, while the electrolyte conversion rate in Embodiment 2 is 96.2%. The electrolyte conversion rate in Embodiment 2 is higher than that in Comparative Example 1, indicating that the catalytic property of Embodiment 2 is higher than that of the catalyst in Comparative Example 1. After 300 cycle tests, the electrolyte conversion rate in Comparative Example 1 remains at 62.3%, while the electrolyte conversion rate in Embodiment 2 is 95.6%, indicating that the stability of the catalyst in Embodiment 2 is better than that in Comparative Example 1. This fully reflects the effect of Ag in improving the catalytic efficiency. The Ag-TaON catalyst is obtained by reducing the catalyst in Comparative Example 2 with sodium borohydride and the Ag-TaON catalyst is obtained by photodeposition in Embodiment 2.Although the contents of the catalyst Ag in Comparative Example 2 and Embodiment 2 are the same, the conversion rate of Comparative Example 2 is only 85.3% with the same amount of Ag, and after 300 cycle tests, the conversion rate is only 67.7%, so the property of Comparative Example 2 is far lower than that of Embodiment 2. In this way, it is indicated that the property of the catalyst obtained by the reduction method of the present invention is superior to that of the traditional method.

TABLE-US-00001 Comparison of photodegradation properties of electrolytes in Example 2 with that of Comparative Examples 1 and 2 Degradation rate Cycle property (conversion rate after 300 cycles) Comparative Example 1 73.2% 62.3% Comparative Example 2 85.3% 67.7% Embodiment 2 96.2% 95.6%

[0092] The photocatalyst and the application thereof in the environmentally friendly photocatalytic treatment of the power battery provided by the present invention have been introduced in detail above, and the principle and implementation of the present invention have been illustrated with specific embodiments. The explanation of the above embodiments is only used to help understand the method and the core idea of the present invention, including the best mode, and also enables any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be pointed out that for those of ordinary skills in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention. The protection scope of the present invention is defined by the claims, and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements that are not different from the literal expression of the claims, or if they include equivalent structural elements that are not materially different from the literal expression of the claims, these other embodiments should also be included in the scope of the claims.