A hollow core-shell structure Cu 2-x S@XO m Preparation method and its application in visible light-catalyzed hydrogen production from ammonia boran alcoholysis

Abstract

This invention discloses a hollow core-shell structure Cu 2‑x S@XO m The preparation method of the present invention uses an etching-epitaxy growth method to prepare hollow core-shell Cu. 2‑x S@XO m The two stages are relatively independent, and their microstructures can be controllably adjusted by controlling the process conditions. This is particularly relevant in the preparation of hollow Cu. 2‑x When using S-cubic cells, the thickness of the hollow core layer can be precisely controlled by adjusting the sulfidation and etching times. During the epitaxial growth stage, the shell thickness can also be controlled by adjusting the concentration of the copper-cobalt-nickel solution and the immersion time. Furthermore, the synthesis process uses only some inexpensive reagents, resulting in low costs and easy scalability for mass production.

Description

Technical Field

[0001] This invention relates to the field of catalyst preparation technology, and more particularly to a hollow core-shell structure Cu 2-x S@XO m Preparation method and its application in the catalytic hydrogen production from the alcoholysis of ammonia borane under visible light. Background Technology

[0002] Ammonia borane (H3N-BH3) is a representative chemical hydride with a hydrogen content as high as 19.6%. It can produce hydrogen through alcoholysis at room temperature, making it one of the most promising hydrogen storage materials. However, the hydrogen release rate of ammonia borane in methanol is extremely slow, and developing catalysts to accelerate its alcoholysis for hydrogen production has been a key research focus in this field. Numerous studies have confirmed that noble metal-based catalysts have high catalytic activity for the alcoholysis of ammonia borane, but their high cost prevents large-scale application. Some non-noble metal catalysts, such as nickel and copper, or their alloys, have certain catalytic effects in the alcoholysis of ammonia borane for hydrogen production. However, overall, their activity still needs to be improved to meet the industrial demand for rapid hydrogen production. The morphology of nanostructured catalysts has a significant impact on their activity; by controlling the morphology and structure of catalysts, it is hoped that catalytic materials with high catalytic activity can be obtained. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a hollow core-shell Cu structure with low preparation cost and controllable process. 2-x S@XO m Preparation method; the hollow core-shell Cu obtained by the method of the present invention 2-x S@XO m It exhibits high activity as a catalyst in the visible light-induced alcoholysis of ammonia borane to produce hydrogen.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0005] A hollow core-shell structure Cu 2-x S@XO m The preparation method includes the following steps:

[0006] (1) Dissolve a certain amount of divalent copper salt in water and stir to form a homogeneous solution;

[0007] (2) Add a certain concentration of NaOH solution dropwise into the above solution to form mixed solution A, and stir for 15 to 60 minutes;

[0008] (3) Add a certain concentration of ascorbic acid solution to the above solution, soak for 1-5 hours, and then filter and wash the Cu2O solid product.

[0009] (4) Disperse the collected solid powder in a certain amount of deionized water, add a certain amount of Na2S solution, stir for 15-60 min, and filter to collect solid sample Cu2O@CuS;

[0010] (5) Disperse the above powder in 30 mL of methanol, add HCl solution to the solution, and continue stirring for 2–10 min to obtain hollow Cu. 2-x S;

[0011] (6) Weigh Cu 2-x The S precursor was dispersed in a certain amount of ethanol, and then a certain amount of soluble cobalt salt and / or nickel salt was added. After ultrasonic dispersion for a period of time, the mixture was stirred for another period of time.

[0012] (7) The above solution is transferred to an oven and dried at a certain temperature for 4-10 hours. Finally, the solid is transferred to a tube furnace and calcined for a period of time under a nitrogen atmosphere.

[0013] Preferably, the divalent copper salt in step (1) is copper chloride.

[0014] Preferably, the soluble cobalt salt in step (6) includes cobalt nitrate.

[0015] Preferably, the soluble nickel salt in step (6) includes nickel nitrate.

[0016] Preferably, the concentration of the ascorbic acid solution in step (3) is 0.6 mol / L.

[0017] Preferably, the concentration of hydrochloric acid in step (5) is 2 mol / L.

[0018] Preferably, in step (7), the oven temperature is 80 degrees, the calcination temperature is 350 degrees, and the calcination time is 4 hours.

[0019] Preferably, the concentration of the NaOH solution in step (7) is 2 mol / L.

[0020] The hollow core-shell Cu structure prepared by the above method is described in this invention. 2-x S@XO m Application as a catalyst in the visible light-induced catalytic hydrolysis of ammonia borane to produce hydrogen.

[0021] This invention synthesizes hollow core-shell structured copper sulfide@copper cobalt nickel oxide (using Cu 2-x S@XO m Indicates that Cu 2-x S is a hollow core layer, XO m(where X represents one, two, or three of the cobalt, nickel, and copper elements) This is an ammonia boran alcoholysis hydrogen production catalyst. Firstly, the hollow structure helps reduce catalyst dosage and lower costs. Secondly, hollow catalysts can be used as nanoreactors, confining reactants within the cavity and further improving reaction efficiency. Thirdly, under illumination, the diffusion distance of photogenerated carriers in hollow photocatalysts is shorter than that in corresponding solid materials, which improves the efficiency of photogenerated electron-hole analysis and thus enhances catalytic activity. Finally, charge transfer between the core and shell layers of the hollow core-shell structure can optimize the electronic structure of active sites, improving its intrinsic activity. Currently, synthesizing hollow core-shell catalytic materials is quite difficult; we used an etching-epitaxy growth process to synthesize hollow Cu core-shell catalysts. 2-x S@XO m By optimizing the catalyst composition, a catalyst for hydrogen production from ammonia boron alcoholysis with excellent catalytic activity was obtained. Under xenon lamp-simulated visible light irradiation, the TOF value for hydrogen production from alcoholysis reached 23.5 mol%. hydrogen min -1 mol cat -1 . Attached Figure Description

[0022] Figure 1 The core-hollow Cu core in Embodiment 4 of this invention 2-x SEM image of the S-structure;

[0023] Figure 2 The hollow core-shell structure Cu in Embodiment 4 of the present invention 2-x SEM images of S@Co3O4;

[0024] Figure 3 Hollow core-shell structure Cu in Example 4 2-x XRD pattern of S@Co3O4. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention are described clearly and completely below, but they do not constitute a limitation on the scope of protection of the present invention.

[0026] Hollow core-shell structures are a new class of materials that have emerged in recent years. Currently reported synthesis methods generally struggle to precisely control the thickness of the core and shell layers, which negatively impacts their performance. This invention utilizes an etching-epitaxy growth method to prepare hollow core-shell Cu materials. 2-x S@XO m The two stages are relatively independent, and their microstructures can be controllably adjusted by controlling the process conditions. This is particularly relevant in the preparation of hollow Cu. 2-xWhen using S-cubic cells, the thickness of the hollow core layer can be precisely controlled by adjusting the sulfidation and etching times. During the epitaxial growth stage, the shell thickness can also be controlled by adjusting the concentration of the copper-cobalt-nickel solution and the immersion time. Furthermore, the synthesis process uses only some inexpensive reagents, resulting in low costs and easy scalability for mass production.

[0027] Example 1

[0028] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.1 mmol of cobalt nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 2.3 mol. hydrogen min -1 mol cat -1 .

[0029] Example 2

[0030] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.2 mmol of cobalt nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 7.8 mol. hydrogen min -1 mol cat -1 .

[0031] Example 3

[0032] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. Weigh 50 mg of the precursor and disperse it in 20 mL of ethanol, then add 0.3 mmol of cobalt nitrate, sonicate for 20 min, and stir for 30 min. Transfer the solution to an oven and dry at 80°C for 4-10 hours. Finally, transfer the solid to a tube furnace and calcine at 350°C for 4 hours under a nitrogen atmosphere. Using the above method, 14.5 mol... hydrogen min-1 mol cat -1 .

[0033] Example 4

[0034] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.4 mmol of cobalt nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits high catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 23.5 mol%. hydrogen min -1 mol cat -1 .

[0035] Example 5

[0036] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.5 mmol of cobalt nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits high catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 17.9 mol. hydrogen min -1 mol cat -1 .

[0037] Example 6

[0038] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.6 mmol of cobalt nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits high catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 15.4 mol. hydrogen min -1 mol cat -1 .

[0039] Example 7

[0040] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.2 mmol of copper nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 3.4 mol / L. hydrogen min -1 mol cat -1 .

[0041] Example 8

[0042] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.4 mmol of copper nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 4.5 mol / L. hydrogen min -1 mol cat -1 .

[0043] Example 9

[0044] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.6 mmol of copper nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis, with a TOF value reaching 4.3 mol. hydrogen min -1 mol cat -1 .

[0045] Example 10

[0046] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.2 mmol of nickel nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 41.1 mol. hydrogen min -1 mol cat -1 .

[0047] Example 11

[0048] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.4 mmol of nickel nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 1.9 mol. hydrogen min -1 mol cat -1 .

[0049] Example 12

[0050] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.6 mmol of nickel nitrate was added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 1.5 mol. hydrogen min -1 mol cat -1 .

[0051] Example 13

[0052] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.2 mmol of nickel nitrate and 0.2 mmol of cobalt nitrate were added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits certain catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 8.9 mol / L. hydrogen min -1 mol cat -1 .

[0053] Example 14

[0054] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.2 mmol of nickel nitrate and 0.2 mmol of copper nitrate were added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits high catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 16.8 mol. hydrogen min -1 mol cat -1 .

[0055] Example 15

[0056] Dissolve 1.0 mmol CuCl2·2H2O in 100 mL of deionized water, then add 10 mL of NaOH (2M) solution dropwise to the solution and continue stirring for 30 min. Add 10 mL of ascorbic acid (0.6M) dropwise to the solution and age for 3 h. Finally, filter, wash three times with deionized water and ethanol, and dry under vacuum. Weigh 0.1 g of the powder sample obtained in the previous step and disperse it in 60 mL of deionized water, stir for 10 min, then add 40 mL of Na2S solution (6.25 mM) to the solution and continue stirring for 25 min. Filter to collect the solid powder sample and dry it. Disperse 0.1 g of the sample obtained in the previous step in 30 mL of methanol and stir for at least 15 min, then add 5 mL of HCl solution (2M) to the solution and continue stirring for 3 min. Filter to collect the solid powder sample and dry it. 50 mg of the precursor was weighed and dispersed in 20 mL of ethanol, then 0.2 mmol of cobalt nitrate and 0.2 mmol of copper nitrate were added. The mixture was ultrasonically dispersed for 20 min and stirred for 30 min. The solution was then transferred to an oven and dried at 80°C for 4–10 hours. Finally, the solid was transferred to a tube furnace and calcined at 350°C for 4 hours under a nitrogen atmosphere. The catalyst prepared by the above method exhibits high catalytic activity in the hydrogen production reaction of ammonia borane alcoholysis under visible light irradiation, with a TOF value reaching 19.4 mol. hydrogen min -1 mol cat -1 .

[0057] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a hollow core-shell structure Cu 2-x S@XO m , wherein Cu 2-x S is a hollow core layer, XO m is a shell layer, X represents one, two or three of cobalt, nickel and copper, characterized in that Includes the following steps: (1) Dissolve a certain amount of divalent copper salt in water and stir to form a homogeneous solution; (2) Add a certain concentration of NaOH solution dropwise into the above solution to form mixed solution A, and stir for 15 to 60 min; (3) Add a certain concentration of ascorbic acid solution to the above solution, age for 1-5 h, and filter and wash the Cu2O solid product. (4) Disperse the collected solid powder in a certain amount of deionized water, add a certain amount of Na2S solution, stir for 15-60 min, and filter to collect solid sample Cu2O@CuS. (5) The powder is dispersed in 30 mL of methanol, and a solution of HCl is added to the solution, and stirring is continued for 2-10 min to obtain hollow Cu 2-x S; (6) Weigh Cu 2-x The S precursor is dispersed in a certain amount of ethanol, and then a certain amount of one or more of soluble cobalt salt, copper salt, and nickel salt is added. After ultrasonic dispersion for a period of time, continue stirring for a period of time. (7) The above solution is transferred to an oven and dried at a certain temperature for 4-10 hours. Finally, the solid is transferred to a tube furnace and calcined for a period of time under a nitrogen atmosphere.

2. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: The divalent copper salt mentioned in step (1) is copper chloride.

3. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: The soluble cobalt salt in step (6) includes cobalt nitrate.

4. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: The soluble nickel salt in step (6) includes nickel nitrate.

5. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: In step (3), the concentration of ascorbic acid solution is 0.6 mol / L.

6. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: In step (5), the concentration of hydrochloric acid is 2 mol / L.

7. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: In step (7), the oven temperature is 80℃, the calcination temperature is 350℃, and the calcination time is 4 hours.

8. A hollow core-shell structure Cu as described in claim 1 2-x S@XO m The preparation method is characterized by: In step (7), the concentration of the NaOH solution is 2 mol / L.

9. A hollow core-shell structure Cu 2-x S@XO m Its characteristics are, The method described in any one of claims 1-8 is used to prepare the product.

10. Hollow core-shell structure Cu prepared by the method according to any one of claims 1-8. 2-x S@XO m application as a catalyst for the catalytic hydrogen production from the alcoholysis of ammonia borane under visible light.

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