Method for prepareing copper-nickel cobaltate nanowire

Abstract

A method for preparing copper-nickel cobaltate nanowires includes steps of: (1) dissolving a soluble nickel salt, cobalt salt and copper salt in ultrapure water, and preparing same into a mixed salt solution A; (2) adding 1-4 mmol of sodium dodecyl sulfate to solution A, and dissolving same with stirring; (3) dissolving 12-30 mmol of hexamethylenetetramine in 20 mL of ultrapure water to form solution B; (4) slowly dropwise adding solution B to solution A via a separatory funnel to form solution C, and stirring same for 0.5-1 h; and (5) further transferring same into a 100 mL reaction vessel, reacting same at 100-160° C. for 8-20 h, suction filtration and washing, and drying same at 40-60° C. in a vacuum oven, and further reacting same at 350-800° C. for 1-4 h in a muffle furnace.

Claims

1. A method for preparing copper-nickel cobaltate nanowires, comprising steps of: (1) dissolving a soluble nickel salt, cobalt salt and copper salt in ultrapure water, and preparing same into a mixed salt solution A; (2) adding 1-4 mmol of sodium dodecyl sulfate to the solution A, and dissolving same with stirring; (3) dissolving 12-30 mmol of hexamethylenetetramine in 20 mL of ultrapure water to form a solution B; (4) slowly dropwise adding the solution B to the solution A via a separatory funnel to form a solution C, and stirring same for 0.5-1 hour; and (5) then transferring the solution C into a 100 mL reaction vessel, reacting same at 100-160° C. for 8-20 h, carrying out suction filtration and washing, drying same at 40-60° C. in a vacuum oven, and further reacting same at 350-800° C. for 1-4 hours in a muffle furnace.

2. The method for preparing copper-nickel cobaltate nanowires according to claim 1, wherein a mixed salt solution A with a molar ratio 2:1 of Co.sup.2+/(Ni.sup.2+, Cu.sup.2+) is prepared in the step (1), the molar ratio of Co.sup.2+/(Ni.sup.2+, Cu.sup.2+) represents ratio of amount of Co.sup.2+ over total amount of Ni.sup.2+ and Cu.sup.2+.

3. The method for preparing copper-nickel cobaltate nanowires according to claim 2, wherein the soluble nickel salt in the step (1) is selected from one of nickel chloride hexahydrate, nickel sulfate heptahydrate, nickel(II) nitrate hexahydrate, nickel chloride, nickel sulfate and nickel nitrate.

4. The method for preparing copper-nickel cobaltate nanowires according to claim 3, wherein the soluble cobalt salt in the step (1) is selected from one of cobalt acetate tetrahydrate, cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt chloride hexahydrate, cobalt sulfate heptahydrate, and cobalt(II) nitrate hexahydrate.

5. The method for preparing copper-nickel cobaltate nanowires according to claim 4, wherein the soluble copper salt is selected from one of copper chloride dihydrate, copper sulfate pentahydrate and copper nitrate.

6. The method for preparing copper-nickel cobaltate nanowires according to claim 1, wherein the soluble nickel salt in the step (1) is selected from one of nickel chloride hexahydrate, nickel sulfate heptahydrate, nickel(II) nitrate hexahydrate, nickel chloride, nickel sulfate and nickel nitrate.

7. The method for preparing copper-nickel cobaltate nanowires according to claim 6, wherein the soluble cobalt salt in the step (1) is selected from one of cobalt acetate tetrahydrate, cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt chloride hexahydrate, cobalt sulfate heptahydrate, and cobalt(II) nitrate hexahydrate.

8. The method for preparing copper-nickel cobaltate nanowires according to claim 7, wherein the soluble copper salt is selected from one of copper chloride dihydrate, copper sulfate pentahydrate and copper nitrate.

9. The method for preparing copper-nickel cobaltate nanowires according to claim 1, wherein the soluble cobalt salt in the step (1) is selected from one of cobalt acetate tetrahydrate, cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt chloride hexahydrate, cobalt sulfate heptahydrate, and cobalt(II) nitrate hexahydrate.

10. The method for preparing copper-nickel cobaltate nanowires according to claim 9, wherein the soluble copper salt is selected from one of copper chloride dihydrate, copper sulfate pentahydrate and copper nitrate.

11. The method for preparing copper-nickel cobaltate nanowires according to claim 1, wherein the soluble copper salt is selected from one of copper chloride dihydrate, copper sulfate pentahydrate and copper nitrate.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The foregoing and other exemplary purposes, aspects and advantages of the present invention will be better understood in principle from the following detailed description of one or more exemplary embodiments of the invention with reference to the drawings, in which:

(2) FIG. 1 is an SEM image of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention.

(3) FIG. 2 is a TEM image of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention.

(4) FIG. 3 is a BET test curve of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention.

(5) FIG. 4 is an XRD test curve of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention.

(6) FIG. 5 is a comparison of catalytic performance for hydrogen production with Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 and CuCo.sub.2O.sub.4, NiCo.sub.2O.sub.4 prepared according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(7) The invention will now be described in detail through several embodiments with reference to the accompanying drawings.

First Embodiment

(8) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (2 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 1.2 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 30 min, transferred to a reaction vessel, reacted for 12 h (hours) at 120° C. (Celsius), carried out with suction filtration and washed, and dried under a vacuum oven 40° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(9) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 600° C. at a heating rate of 2° C./min, and kept for 2 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 was obtained by taking out a sample.

(10) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

Second Embodiment

(11) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (2 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 0.6 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 30 min, transferred to a reaction vessel, reacted for 12 h at 120° C., carried out with suction filtration and washed, and dried under a vacuum oven 60° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(12) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 600° C. at a heating rate of 2° C./min, and kept for 2 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 was obtained by taking out a sample.

(13) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

Third Embodiment

(14) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (4 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 1.2 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 60 min, transferred to a reaction vessel, reacted for 12 h at 120° C., carried out with suction filtration and washed, and dried under a vacuum oven 40° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(15) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 600° C. at a heating rate of 2° C./min, and kept for 4 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 was obtained by taking out a sample.

(16) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

Fourth Embodiment

(17) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (2 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 1.2 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 30 min, transferred to a reaction vessel, reacted for 8 h at 160° C., carried out with suction filtration and washed, and dried under a vacuum oven 40° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(18) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 600° C. at a heating rate of 2° C./min, and kept for 2 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.2 was obtained by taking out a sample.

(19) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

Fifth Embodiment

(20) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (2 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 1.5 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 30 min, transferred to a reaction vessel, reacted for 20 h at 100° C., carried out with suction filtration and washed, and dried under a vacuum oven 40° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(21) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 600° C. at a heating rate of 2° C./min, and kept for 2 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.2 was obtained by taking out a sample.

(22) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

Sixth Embodiment

(23) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (2 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 1.2 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 30 min, transferred to a reaction vessel, reacted for 12 h at 120° C., carried out with suction filtration and washed, and dried under a vacuum oven 40° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(24) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 800° C. at a heating rate of 2° C./min, and kept for 2 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.2 was obtained by taking out a sample.

(25) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

Seventh Embodiment

(26) Preparation of a precursor: cobalt acetate (2 mmol), sodium dodecyl sulfate (2 mmol), nickel chloride (x mmol), copper chloride (1-x mmol) were dissolved in 20 mL water (0≤x≤1), and stirred magnetically until dissolved, then 1.2 M hexamethylenetetramine solution (20 mL) was added, and the obtained solution was stirred magnetically for 30 min, transferred to a reaction vessel, reacted for 12 h at 110° C., carried out with suction filtration and washed, and dried under a vacuum oven at 40° C. to obtain a precursor M(OH).sub.2, wherein M is one of nickel, copper and cobalt (i.e. Ni(OH).sub.2, Cu(OH).sub.2 and Co(OH).sub.2).

(27) Preparation of nanowire-shaped Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4: the dried precursor was uniformly ground in a mortar, placed in a muffle furnace, heated to 350° C. at a heating rate of 2° C./min, and kept for 2 h; and after it was cooled to room temperature, a target product Cu.sub.xNi.sub.1-xCo.sub.2O.sub.2 was obtained by taking out a sample.

(28) Through measurement, the morphology of the Cu.sub.xNi.sub.1-xCo.sub.2O.sub.4 obtained in the invention is still a nanowire structure.

(29) The structure and properties of the composite cobaltate prepared according to the present invention are analyzed and tested by taking nanowire Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 as an example.

(30) 1. SEM Analysis

(31) FIG. 1 is an SEM image of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention. As can be seen from the scan diagram, the morphology of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 synthesized through hydrothermal synthesis is nanowires with a diameter of about 30 nm.

(32) 2. TEM Test

(33) FIG. 2 is a TEM image of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention, and a nanowire-shaped catalyst can be further confirmed from the projection view.

(34) 3. BET Test

(35) FIG. 3 is a nitrogen adsorption and desorption isotherm curve and a pore size distribution curve of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention, and it can be seen from the figure that the isotherm is classified into a type IV isotherm, and the isotherm has an obvious hysteresis ring in the range of relative pressure of 0.45-0.98, which indicates that mesopores exist in the material. From the pore size distribution curve it can be found that the pores are mainly concentrated at 4 nm.

(36) 4. XRD

(37) FIG. 4 is an XRD test of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention. The characteristic peaks of different crystal planes of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 are marked in the figure.

(38) 5. Test of Catalytic Performance for Hydrogen Production

(39) FIG. 5 is a performance test of Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 prepared according to the present invention as a catalyst for ammonia borane hydrolysis to produce hydrogen, the amount of NH.sub.3BH.sub.3 is 3 mmol, NaOH is 20 mmol, and the catalyst is 5 mg. The test showed that it produced 55 mL of hydrogen in the first minute by taking Cu.sub.0.6Ni.sub.0.4Co.sub.2O.sub.4 as a catalyst at 25° C., about 24 mL of hydrogen in the first minute by taking CuCo.sub.2O.sub.4 as a catalyst, and no hydrogen in the first minute by taking NiCo.sub.2O.sub.4 as a catalyst.

(40) While the invention has been described in terms of several exemplary embodiments, those skilled on the art will recognize that the invention can be practiced with modification within the spirit and scope of the appended claims. In addition, it is noted that, the Applicant's intent is to encompass equivalents of all claim elements, even if amended later during prosecution.