AgCl / CuO nano-catalyst and preparation method thereof

Abstract

The invention relates to the technical field of nano-catalysts, and discloses a preparation method of an AgCl / CuO nano-catalyst, which comprises the following steps: taking a copper source and silver metal salt as raw materials, taking deionized water as a solvent, adding an alkali source to synthesize an AgCl / Cu (OH) 2 nano-material, and calcining to obtain the AgCl / CuO nano-catalyst. The preparation method comprises the following specific steps: step 1, dissolving 0.2 mmol of copper chloride dihydrate or copper nitrate trihydrate in 25 mL of deionized water, uniformly stirring, preparing 2 mL of a 16 M alkali source, adding the alkali source into the previous solution, and fully stirring for 30 minutes to obtain a Cu (OH) 2 aqueous solution; 2, 0.085 g of silver nitrate solid is taken and dissolved in 10 mL of deionized water, and a 0.05 M silver nitrate aqueous solution is obtained; the preparation method of the AgCl / CuO nano-catalyst provided by the invention is simple in process, mild in reaction condition and low in raw material price, and the prepared catalyst has a unique nanobelt morphology, can realize large-scale synthesis, and has a relatively wide application prospect in actual large-scale industrial application.

Description

Technical Field

[0001] The invention relates to the technical field of nano catalysts, and in particular to an AgCl / CuO nano catalyst and a preparation method thereof. Background Art

[0002] The massive emission of greenhouse gas carbon dioxide (CO2) has had a severe negative impact on the global climate and energy economy. Therefore, the development of efficient and clean CO2 catalytic technology to convert it into high value-added chemical products has attracted widespread attention from scientific researchers. Using renewable electricity to turn CO2 into treasure provides an effective solution for carbon emission reduction and energy storage, and the core lies in how to develop efficient electrocatalysts.

[0003] Studies have shown that metal oxide electrocatalysts can highly selectively reduce carbon dioxide to C1 products, such as methanol and carbon monoxide. However, for the reduction of CO2 to C 2+ The products, especially the ethylene product with higher energy density, still face problems such as low selectivity and poor stability. This is because the process of CO2 reduction to ethylene involves the generation of multiple reactive intermediates, which in turn leads to the diversity of reduction products. Therefore, the development of metal oxide electrocatalysts with high ethylene selectivity remains challenging.

[0004] At present, copper-based oxide nanocatalysts have become the hottest catalytic materials for electroreduction of CO2 to produce ethylene products due to their high CO2 conversion activity and suitable binding energy for carbon-containing intermediates. Recent studies have shown that the doping effect of other metal or non-metal components can optimize the electronic structure of copper oxide catalysts, stabilize the adsorption of intermediates *CO and reduce the reaction barrier of CC coupling, thus achieving C 2+ However, conventional copper oxide doping strategies often require harsh reaction conditions.

[0005] Therefore, the present invention proposes a simple, large-scale, mild preparation method of AgCl / CuO electrocatalyst. In the preparation process, the special porous nanobelt morphology of CuO provides more space for the loading of AgCl, which is conducive to the better adsorption of carbon dioxide molecules during the carbon dioxide electrocatalysis process, and is used for catalyzing CO2 reduction to produce ethylene with high selectivity and high activity. At the same time, the ethylene produced in the catalytic CO2 electroreduction has a Faraday efficiency of up to 72%. Summary of the invention

[0006] In order to solve the technical problems raised in the background technology, the present invention provides a method for preparing a AgCl / CuO nanocatalyst.

[0007] The present invention is realized by the following technical scheme: a preparation of an AgCl / CuO nanocatalyst, wherein: CuO exists in the form of nanobelts with a porous structure and rich in high grain boundary density, and AgCl nanoparticles are evenly distributed on the CuO nanobelt carrier to expose more active sites. The catalyst has low raw material price, simple preparation process, mild reaction conditions, and the prepared catalyst is applied to electrochemical ethylene production test in neutral electrolyte and shows excellent high activity, stability, and high selectivity (ethylene Faraday efficiency is as high as 72%).

[0008] The present invention provides a method for preparing a AgCl / CuO nanocatalyst, which comprises the following steps: Using copper source and silver metal salt as raw materials, deionized water as solvent, and adding alkali source, AgCl / Cu(OH)2 nanomaterials are synthesized, and then AgCl / CuO nanocatalysts are obtained by calcination.

[0009] The more specific steps are as follows: Step 1: Dissolve 0.2 mmol of copper chloride dihydrate or copper nitrate trihydrate in 25 mL of deionized water and stir evenly. Then prepare 2 mL of 16 M alkali source and add it to the previous solution. Stir well for 30 minutes to obtain a Cu(OH)2 aqueous solution. Step 2, take 0.085 g of silver nitrate solid and dissolve it in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3, add 1 mL of 0.05 MAgNO3 aqueous solution to the Cu(OH)2 solution prepared in step 1, react for 10 minutes, wash with deionized water, ethanol and cyclohexane respectively, then ultrasonically disperse evenly in 5 mL of cyclohexane, freeze-dry overnight to obtain AgCl / Cu(OH)2 precursor; Step 4: calcine the obtained AgCl / Cu(OH)2 precursor at 250°C for 10 min to obtain AgCl / CuO nanocatalyst.

[0010] Preferably, the alkali source is any one of potassium hydroxide, sodium hydroxide and ethylenediamine.

[0011] Preferably, the copper chloride dihydrate, copper nitrate trihydrate, silver nitrate, sodium hydroxide, potassium hydroxide and ethylenediamine are all analytically pure.

[0012] Preferably, the molar ratio of AgCl to CuO in the AgCl / CuO nanocatalyst is 1:4, that is, 25% AgCl / CuO.

[0013] Preferably, the washing method is to use deionized water, ethanol, cyclohexane for cleaning, centrifugation, storage in cyclohexane, and vacuum drying for storage.

[0014] Preferably, in step 3, the mixing method of silver nitrate and copper hydroxide (ie, copper source and alkali source) is a liquid phase physical mixing method to prepare the desired AgCl / Cu(OH)2 precursor.

[0015] Preferably, the calcination is carried out in air, and the obtained catalyst material is stored under dry conditions at room temperature.

[0016] The present invention also proposes a method for preparing ethylene by electrocatalytic water decomposition, the specific steps of which are as follows: Weigh 1 mg of the AgCl / CuO catalyst prepared by the above method, disperse it in 0.1 mL of a mixed solution containing isopropanol and naphthol in a volume ratio of 9:1, and perform ultrasonic dispersion for 30 min to obtain a uniformly dispersed mixed solution; Use a 10 uL pipette to take 4 uL of the evenly dispersed mixture and apply it twice on a glassy carbon electrode with an area of ​​3 x 3 mm². The glassy carbon electrode coated with the catalyst is directly used as the working electrode after drying, and the Ag / AgCl electrode is used as the reference electrode, and a 1 x 1 cm² platinum sheet electrode is used as the counter electrode to form a three-electrode system. The electrocatalytic water decomposition to produce ethylene test is carried out in an electrolyte of 0.5 MKHCO3.

[0017] At the beginning of the test, specifically, the AgCl / CuO catalyst needs to be reconstructed at a potential of -1.1 V (vs. RHE) for 30 min before coating to obtain the Ag / Cu catalyst. Linear sweep voltammetry (LSV) is used in the test to explore the electrocatalytic activity of the catalyst, and the change of current over time at a fixed potential is tested by constant potential method to illustrate the stability of the catalyst, and the performance of the catalyst prepared in the present invention is compared with the performance of other CuO-related catalysts.

[0018] Preferably, the mass of the catalyst loaded on the glassy carbon electrode is 0.04 mg, the LSV scan rate is 10 mV / s, and the test potential range is -2 to 0 V.

[0019] By adopting the above technical scheme, at room temperature, using copper source (copper chloride dihydrate, copper nitrate trihydrate) and silver metal salt as raw materials, deionized water as solvent, adding alkali source (such as potassium hydroxide, sodium hydroxide, ethylenediamine), AgCl / Cu(OH)2 nanomaterials are synthesized, and then AgCl / CuO nanocatalysts are obtained by calcination.

[0020] The preparation process is simple and novel, the reaction conditions are mild, and the time consumption is short. The prepared composite catalyst has unique morphological characteristics; it can efficiently and quickly reduce CO2 in the atmosphere to organic chemical raw materials, such as carbon monoxide, methane, and ethylene, and exhibits excellent Faradaic efficiency in the preparation of ethylene. Therefore, the synthesis method of the AgCl / CuO catalyst has important application value in large-scale industrial practical applications.

[0021] Compared with the prior art, the present invention has the following beneficial effects: The method for preparing AgCl / CuO nanocatalyst provided by the present invention has simple process, mild reaction conditions and cheap raw materials. The prepared catalyst has unique nanobelt morphology, can be synthesized in large quantities, and has broad application prospects in actual large-scale industrial applications.

[0022] The catalyst prepared by the present invention was applied to electrochemical ethylene production tests in neutral electrolyte and showed excellent high activity, stability, and high selectivity (ethylene Faraday efficiency was as high as 72%), which has great advantages in catalytic CO2 reduction performance and selectivity compared with the currently reported CuO-related catalysts. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of a method for preparing a AgCl / CuO nanocatalyst proposed by the present invention; Figure 2 The present invention relates to a synthesis picture of a precursor nanomaterial with a molar ratio of 25% AgCl / Cu(OH)2; Figure 3 The present invention relates to a transmission electron microscope (STEM-EDS) image of a nanomaterial having a molar ratio of 25% AgCl / Cu(OH)2; Figure 4 It is a transmission electron microscopy (STEM-EDS) comparison of Cu(OH)2 powder and AgCl / CuO powder with a molar ratio of 25%; Figure 5 The present invention relates to a transmission electron microscopy (STEM-EDS) image of Ag / Cu powder after the catalyst is reconstructed at -1.1 V (vs. RHE) for 30 min; Figure 6 The HRTEM image of the AgCl / CuO powder with a molar ratio of 25% according to the present invention; Figure 7 The X-ray diffraction (XRD) diagrams of the present invention using 1%, 10%, 25%, 50%, and 100% molar ratio AgCl / CuO catalysts (corresponding to sample 1, sample 2, sample 3, sample 4, and sample 5, respectively); Figure 8The present invention relates to an X-ray diffraction (XRD) diagram of a 25% AgCl / CuO catalyst and its precursor AgCl / Cu(OH)2; Fig. 9 The linear sweep voltammetry (LSV) curves of the present invention using 1%, 10%, 25%, 50%, and 100% molar ratio AgCl / CuO powders (corresponding to sample 1, sample 2, sample 3, sample 4, and sample 5, respectively, in order); Fig.10 It is a linear sweep voltammetry (LSV) graph of 25% AgCl / CuO powder synthesized by using copper chloride dihydrate and copper nitrate trihydrate in the present invention; Fig.11 1 is a performance diagram of AgCl / CuO powder catalysts with a molar ratio of 1%, 10%, 25%, 50%, and 100% (corresponding to sample 1, sample 2, sample 3, sample 4, and sample 5, respectively) at -1 V (vs. RHE) according to the present invention; Fig.12 The present invention relates to a performance diagram of AgCl / CuO powder with a molar ratio of 25% at different potentials; Fig.13 This is the infrared spectrum (FT-IR) of AgCl / CuO powder with a molar ratio of 25% used in the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment.

[0025] Embodiment 1: Reference Figure 1 The present invention provides a method for preparing a AgCl / CuO nanocatalyst, which comprises the following steps: Step 1: Dissolve 0.2 mmol of cupric chloride dihydrate in 25 mL of deionized water and stir evenly. Prepare 2 mL of 16 M NaOH aqueous solution and add it to the previous solution. Stir thoroughly for 30 minutes to obtain a Cu(OH)2 aqueous solution.

[0026] Step 2, take 0.085 g of silver nitrate solid and dissolve it in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3: Add 1 mL of 0.05 MAgNO3 aqueous solution to the Cu(OH)2 solution prepared above, react for 10 minutes, wash with deionized water, ethanol and cyclohexane respectively, and then disperse evenly in 5 mL of cyclohexane with ultrasound, freeze-dry overnight to obtain AgCl / Cu(OH)2 precursor.

[0027] Step: 4: Calcine the obtained AgCl / Cu(OH)2 precursor at 250°C for 10 min to obtain AgCl / CuO nanocatalyst.

[0028] Embodiment 2: The present invention provides a method for preparing a AgCl / CuO nanocatalyst, which comprises the following steps: Step 1: Dissolve 0.2 mmol of copper nitrate trihydrate in 25 mL of deionized water and stir evenly. Prepare 2 mL of 16 M NaOH aqueous solution and add it to the previous solution. Stir thoroughly for 30 minutes to obtain a Cu(OH)2 aqueous solution.

[0029] Step 2, take 0.085 g of silver nitrate solid and dissolve it in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3: Add 1 mL of 0.05 MAgNO3 aqueous solution to the Cu(OH)2 solution prepared above, react for 10 minutes, wash with deionized water, ethanol and cyclohexane respectively, and then disperse evenly in 5 mL of cyclohexane with ultrasound, freeze-dry overnight to obtain AgCl / Cu(OH)2 precursor.

[0030] Step: 4: Calcine the obtained AgCl / Cu(OH)2 precursor at 250°C for 10 min to obtain AgCl / CuO nanocatalyst.

[0031] Embodiment 3: The present invention provides a method for preparing a AgCl / CuO nanocatalyst, which comprises the following steps: Step 1: Dissolve 0.2 mmol of cupric chloride dihydrate in 25 mL of deionized water and stir evenly. Prepare 2 mL of 16 M potassium hydroxide aqueous solution and add it to the previous solution. Stir thoroughly for 30 minutes to obtain a Cu(OH)2 aqueous solution.

[0032] Step 2, take 0.085 g of silver nitrate solid and dissolve it in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3: Add 1 mL of 0.05 MAgNO3 aqueous solution to the Cu(OH)2 solution prepared above, react for 10 minutes, wash with deionized water, ethanol and cyclohexane respectively, and then disperse evenly in 5 mL of cyclohexane with ultrasound, freeze-dry overnight to obtain AgCl / Cu(OH)2 precursor.

[0033] Step: 4: Calcine the obtained AgCl / Cu(OH)2 precursor at 250°C for 10 min to obtain AgCl / CuO nanocatalyst.

[0034] Embodiment 4: The present invention provides a method for preparing a AgCl / CuO nanocatalyst, which comprises the following steps: Step 1: Dissolve 0.2 mmol of cupric chloride dihydrate in 25 mL of deionized water and stir evenly. Prepare 2 mL of 16 M ethylenediamine aqueous solution and add it to the previous solution. Stir thoroughly for 30 minutes to obtain a Cu(OH)2 aqueous solution.

[0035] Step 2, take 0.085 g of silver nitrate solid and dissolve it in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3: Add 1 mL of 0.05 MAgNO3 aqueous solution to the Cu(OH)2 solution prepared above, react for 10 minutes, wash with deionized water, ethanol and cyclohexane respectively, and then disperse evenly in 5 mL of cyclohexane with ultrasound, freeze-dry overnight to obtain AgCl / Cu(OH)2 precursor.

[0036] Step: 4: Calcine the obtained AgCl / Cu(OH)2 precursor at 250°C for 10 min to obtain AgCl / CuO nanocatalyst.

[0037] Test Example 1: The AgCl / CuO nanocatalyst prepared in Example 1 was used in the test of electrocatalytic water decomposition to produce ethylene.

[0038] First, pre-treat the glassy carbon electrode: polish the glassy carbon electrode with aluminum oxide powder on the chamois velvet in an "8" shape for 2-3 minutes, and then clean the electrode surface with deionized water to remove the polishing residue. After that, the glassy carbon electrode needs to be activated by cyclic voltammetry in a 0.5-1 mol / L H2SO4 solution, with a scanning range of -1 to 1 V, and scan repeatedly until a stable cyclic voltammetry cycle is reached.

[0039] Weigh 1 mg of the AgCl / CuO catalyst obtained in step 4 above, disperse it in 0.1 mL of a mixed solution containing isopropanol:naphthol in a volume ratio of 9:1, and ultrasonically disperse it for 30 min to obtain a uniformly dispersed mixed solution. Use a 10 uL pipette to take 4 uL of the uniformly dispersed mixed solution and drop it twice on a glassy carbon electrode with an area of ​​3 x 3 mm². The glassy carbon electrode coated with the catalyst is directly used as the working electrode after drying, and the Ag / AgCl electrode is used as the reference electrode, and the 1 x 1 cm² platinum sheet electrode is used as the counter electrode to form a three-electrode system. The electrocatalytic water decomposition to ethylene test is carried out in an electrolyte of 0.5 MKHCO3. At the beginning of the test, the catalyst needs to be reconstructed at a potential of -1.1 V (vs. RHE) for 30 min to obtain the Ag / Cu catalyst. Linear sweep voltammetry (LSV) is used in the test to explore the electrocatalytic activity of the catalyst, and the change of current over time at a fixed potential is tested by constant potential method to illustrate the stability of the catalyst.

[0040] Test Example 2: This test example conducts a test on catalytic water decomposition to produce ethylene. The implementation steps are the same as those of Test Example 1, except that the AgCl / CuO nanocatalyst prepared in Example 2 is used for the test. The test results are close to those obtained in Test Example 1.

[0041] Test Example 3: This test example conducts a test on catalytic water decomposition to produce ethylene. The implementation steps are the same as those of Test Example 1, except that the AgCl / CuO nanocatalyst prepared in Example 3 is used for the test. The test results are close to those obtained in Test Example 1.

[0042] Test example 4: This test example conducts a test on catalytic water decomposition to produce ethylene. The implementation steps are the same as those of Test Example 1, except that the AgCl / CuO nanocatalyst prepared in Example 4 is used for the test. The test results are close to those obtained in Test Example 1.

[0043] Test Example 5: This test example conducts a test on catalytic water decomposition to produce ethylene. The implementation steps are the same as those of Test Example 1, except that the reconstruction potential in the test steps is -0.8 V (vs. RHE), and other conditions remain unchanged. The test results are close to those obtained in Test Example 1.

[0044] The test results obtained in the above-mentioned test examples 1-5 are: the Faraday efficiency of ethylene (that is, the ratio between the actual ethylene generated and the theoretical ethylene generated during the electrochemical reduction of carbon dioxide).

[0045] The above technical scheme is adopted, at room temperature, using copper source (copper chloride dihydrate, copper nitrate trihydrate) and silver metal salt as raw materials, deionized water as solvent, adding alkali source (such as potassium hydroxide, sodium hydroxide, ethylenediamine), synthesizing AgCl / Cu(OH)2 nanomaterials, and then calcining to obtain AgCl / CuO nanocatalysts. The preparation process is simple and novel, the reaction conditions are mild, and the time consumption is short. The prepared composite catalyst has unique morphological characteristics; it can efficiently and quickly reduce carbon dioxide in the atmosphere to organic chemical raw materials, such as carbon monoxide, methane, and ethylene, and exhibits excellent Faraday efficiency in the preparation of ethylene. Therefore, the synthesis method of the AgCl / CuO catalyst has important application value in large-scale industrial practical applications.

[0046] In summary, the present invention provides a method for synthesizing a AgCl / CuO mixed catalyst with a special morphology for preparing ethylene. The catalyst has low raw material price, simple preparation process, mild reaction conditions, and the prepared catalyst is applied to electrochemical ethylene production tests in neutral electrolyte and exhibits excellent catalytic activity and stability, with an ethylene Faraday efficiency of up to 72%.

[0047] Further explanation of the drawings in the specification is as follows: Figure 3 The transmission electron microscopy (STEM-EDS) image corresponding to the AgCl / Cu(OH)2 nanomaterial with a molar ratio of 25% shows that AgCl nanoparticles with a size of about 10 nm are uniformly loaded on the Cu(OH)2 porous nanobelts.

[0048] Figure 4 Transmission electron microscopy (STEM-EDS) comparison diagram corresponding to Cu(OH)2 powder and AgCl / CuO powder with a molar ratio of 25%; wherein: Figure 4 The left image corresponds to the transmission electron microscopy (STEM-EDS) image of Cu(OH)2 powder. Figure 4 The right picture corresponds to the transmission electron microscopy (STEM-EDS) picture of the molar ratio of 25% AgCl / CuO; by comparison, the mesoporous structure on the CuO nanobelt can be seen. The right picture shows that the AgCl nanoparticles with a size of about 10nm are uniformly loaded on the CuO porous nanobelt.

[0049] Figure 5 The transmission electron microscopy (STEM-EDS) image of the Ag / Cu powder corresponding to 25% AgCl / CuO reconstructed at -1.1 V (vs. RHE) for 30 min shows that after the electrocatalytic carbon dioxide reaction, uniform Ag / Cu nanoparticles with a size of about 10 nm are formed.

[0050] Figure 6This is a HRTEM image of the AgCl / CuO powder with a molar ratio of 25% according to the present invention. It can be seen that there is a high grain boundary density and interlaced (200) crystal planes of AgCl and (111) crystal planes and (002) crystal planes of CuO, indicating that AgCl is well loaded on the CuO nanobelts.

[0051] Figure 7 Corresponding to the XRD patterns of AgCl / CuO catalysts with different molar ratios, it can be seen that a series of 1%, 10%, 25%, 50%, and 100% AgCl / CuO catalysts (referred to as sample 1, sample 2, sample 3, sample 4, and sample 5) were successfully prepared. It was found that with the increase of AgCl loading, the diffraction peak intensity of AgCl gradually increased. The 1%, 10%, 25%, 50%, and 100% molar ratio AgCl / CuO catalysts were respectively referred to as sample 1, sample 2, sample 3, sample 4, and sample 5, corresponding to Figure 5 AgCl / CuO-1, AgCl / CuO-2, AgCl / CuO-3, AgCl / CuO-4, AgCl / CuO-5.

[0052] Figure 8 Corresponding to the XRD patterns of 25%AgCl / CuO and its precursor, calcination at 250 °C in air atmosphere for 10 min can effectively convert 25%AgCl / Cu(OH)2 into 25%AgCl / CuO.

[0053] Fig. 9 The linear sweep voltammetry (LSV) curves corresponding to 1%, 10%, 25%, 50%, and 100% molar ratio AgCl / CuO powders (referred to as sample 1, sample 2, sample 3, sample 4, and sample 5) show that at a potential of -1 V (vs. RHE), compared with the other four samples, the current density of 25% AgCl / CuO (sample 3) is the largest, reaching 140 mA / cm 2 .

[0054] Fig.10 The linear sweep voltammetry (LSV) curves of 25% AgCl / CuO powders synthesized using different copper sources (copper chloride dihydrate and nitric acid trihydrate) show that the current density of 25% AgCl / CuO catalyst prepared with copper chloride dihydrate as the copper source during the synthesis process is the highest, reaching 140 mA / cm 2 .

[0055] Fig.11The electrocatalytic carbon dioxide reduction performance diagram corresponding to the AgCl / CuO powder catalysts with a molar ratio of 1%, 10%, 25%, 50%, and 100% (recorded as sample 1, sample 2, sample 3, sample 4, and sample 5) at a potential of -1 V (vs. RHE) shows that the main reduction products are hydrogen, carbon monoxide, ethylene, and methane. Compared with the other four samples, 25% AgCl / CuO (sample 3) has the highest ethylene Faraday efficiency (72%) and the lowest hydrogen Faraday efficiency (18%). The performance results show that the 25% AgCl / CuO (sample 3) powder catalyst has the best carbon dioxide electroreduction to ethylene activity and can effectively inhibit the hydrogen evolution side reaction.

[0056] Fig.12 The electrocatalytic carbon dioxide performance diagram corresponding to the molar ratio of 25% AgCl / CuO powder at different potentials shows that the main reduction products are hydrogen, carbon monoxide, ethylene and methane. Compared with other potentials, the highest ethylene Faraday efficiency (72%) and the lowest hydrogen Faraday efficiency (18%) are achieved at a potential of -1 V (vs. RHE). The performance results show that the best carbon dioxide electroreduction to ethylene activity is achieved at a potential of -1 V (vs. RHE), and the hydrogen evolution side reaction can be effectively suppressed.

[0057] Fig.13 From the infrared spectrum (FT-IR) corresponding to 25% AgCl / CuO powder, it can be seen that the characteristic peaks at wave numbers 3447.79 and 1082.55 correspond to the Ag-Cl vibration mode, and the characteristic peaks at wave numbers 1618.16 and 478.2 correspond to the Cu-O vibration mode.

[0058] The above-mentioned embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. An AgCl / CuO nanocatalyst, characterized in that: in: CuO exists in the form of nanobelts with a porous structure and high grain boundary density, and AgCl nanoparticles are uniformly distributed on the CuO nanobelt carrier to expose more active sites for CO2 reduction.

2. A method for preparing the AgCl / CuO nanocatalyst as claimed in claim 1, characterized in that: The method comprises the following steps: taking copper source and silver metal salt as raw materials, taking deionized water as solvent, adding alkali source, synthesizing AgCl / Cu(OH)2 nano material, and then obtaining AgCl / CuO nano catalyst by calcination.

3. The method for preparing a AgCl / CuO nanocatalyst as claimed in claim 2, characterized in that: The specific operations are as follows: Step 1: Dissolve 0.2 mmol of copper chloride dihydrate or copper nitrate trihydrate in 25 mL of deionized water and stir evenly. Then prepare 2 mL of 16 M alkali source and add it to the previous solution. Stir well for 30 minutes to obtain a Cu(OH)2 aqueous solution. Step 2, take 0.085 g of silver nitrate solid and dissolve it in 10 mL of deionized water to obtain a 0.05 M silver nitrate aqueous solution; Step 3, add 1 mL of 0.05 M AgNO3 solution to the Cu(OH)2 solution prepared in step 1, react for 10 minutes, wash with deionized water, ethanol and cyclohexane respectively, then ultrasonically disperse evenly in 5 mL of cyclohexane, freeze-dry overnight to obtain AgCl / Cu(OH)2 precursor; Step 4: calcine the obtained AgCl / Cu(OH)2 precursor at 250°C for 10 min to obtain AgCl / CuO nanocatalyst.

4. The method for preparing a AgCl / CuO nanocatalyst as claimed in claim 3, characterized in that: The alkali source is selected from any one of potassium hydroxide, sodium hydroxide and ethylenediamine.

5. The method for preparing a AgCl / CuO nanocatalyst as claimed in claim 3, characterized in that: The molar ratio of AgCl to CuO in the AgCl / CuO nanocatalyst is 1:4, that is, 25% AgCl / CuO.

6. The method for preparing a AgCl / CuO nanocatalyst as claimed in claim 3, characterized in that: In step 3, the washing method is to wash with deionized water, ethanol and cyclohexane in sequence, collect the solid by centrifugation after each washing, and finally store the solid in cyclohexane for freeze-drying.

7. The method for preparing a AgCl / CuO nanocatalyst as claimed in claim 3, characterized in that: In the step 4, the calcination operation is carried out in air, and the obtained AgCl / CuO nanocatalyst is stored under dry conditions at room temperature.

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