Preparation method of cu3sb s4 nanoparticles and application thereof

Abstract

The present application relates to the technical field of new energy materials and electrochemical catalysis. In order to improve the activity and selectivity of the carbon dioxide reduction catalytic process, the present application provides a preparation method of Cu3SbS4 nanoparticles. First, a certain amount of copper salt is dissolved in water, and under the action of sodium citrate and sodium hydroxide, ascorbic acid is added for reduction. After aging the suspension, the precursor Cu2O is obtained by filtration and drying. Then, antimony salt and Cu2O precursor are coordinated with thioacetamide in an aqueous solution, and the suspension is placed in a high-pressure reaction kettle and kept at 180 DEG C for several hours. After the sample is naturally cooled, the final Cu3SbS4 nanoparticles are obtained by washing and drying. The prepared Cu3SbS4 is used for electrocatalytic reduction of carbon dioxide to prepare CO, and has high selectivity and stability for electrocatalytic reduction of carbon dioxide.

Description

Technical Field

[0001] This invention belongs to the fields of new energy materials technology and electrochemical catalysis technology, specifically relating to a method for preparing Cu3SbS4 nanoparticles and their application. Background Technology

[0002] The continuous accumulation of carbon dioxide in the atmosphere due to the global consumption of fossil fuels has led to problems such as the greenhouse effect, glacial melting, and ocean acidification. Converting carbon dioxide into valuable chemical substances is a possible solution to these problems. There are four main implementation methods: photocatalytic CO2 reduction, biocatalytic CO2 conversion, thermocatalytic reactions, and electrocatalytic reduction. In recent years, electrocatalytic CO2 reduction (CO2RR) has attracted widespread attention. This process allows for controllable potential and reaction temperature, utilizes renewable energy for power, and produces high-value-added industrial chemicals, making it increasingly economically viable.

[0003] Currently, catalysts are mainly classified into four categories based on their binding ability with intermediates: i) Metals such as In, Sn, Cd, and Bi tend to produce formic acid. ii) Au, Ag, and Zn show strong selectivity for CO. iii) Metals such as Ni, Fe, Pt, and Ti are favorable for the electrolysis of water to produce hydrogen evolution, generating H2 as a product. iv) Copper can bind CO* intermediates well, but its binding energy with H* is relatively weak; therefore, metallic copper is the only catalyst that can convert CO* intermediates into C. 2+ The substances that produce the products (such as hydrocarbons and alcohols). Cu-based catalysts have complex selectivity for CO2RR due to their unique electronic properties. By doping with foreign atoms, the electronic relationship between the two can be regulated, affecting their adsorption capacity for reaction intermediates, and ultimately used to regulate CO2RR products.

[0004] Metal sulfides show great promise for applications in hydrogen evolution reaction, photocatalysis, and supercapacitors. Furthermore, the presence of sulfur atoms can stabilize CO2. ·- Intermediates, thereby promoting the electroreduction of CO2. Literature reports that Cu2S with vacancy-modified Cu2S has a Faradaic efficiency (FE) of 8% for n-propanol; while the selectivity (FE) of CuO catalyst modified with a single Sb atom for ethylene is... C2H4 The concentration of CO2 conversion was 58%, because the synergistic effect of Sb sites and oxygen vacancies significantly reduced the dimerization energy of the adsorbed CO* reaction intermediate, thereby promoting the conversion of CO2 to C2H4. Therefore, by doping the catalyst, studying the changes in the electrocatalytic CO2RR selectivity of CuS-based catalysts, and improving the activity and stability of the catalyst, plays an important role in elucidating the changes in the catalyst reaction mechanism.

[0005] Therefore, improving the activity and selectivity of carbon dioxide reduction catalysis by controlling the composition, size, and morphology of CuS-based catalysts has great research prospects and practical significance. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a method for preparing Cu3SbS4 nanoparticles and their applications. This invention uses copper salts, sodium citrate, NaOH, ascorbic acid, antimony salts, and thioacetamide as raw materials. First, Cu2O nanocubic particles are synthesized, and then Cu3SbS4 nanoparticles are synthesized via hydrothermal synthesis. The obtained Cu3SbS4 nanoparticles, through the strong electronic interaction between Cu and Sb elements, alter the catalyst's adsorption capacity for reaction intermediates, causing the catalyst's selectivity to shift between HCOOH and CO, ultimately improving the catalyst's selectivity for C1 products.

[0007] The technical solution adopted in this invention is as follows:

[0008] A method for preparing Cu3SbS4 nanoparticles, characterized by comprising the following steps:

[0009] (1) At room temperature, dissolve the copper salt in ultrapure water, then add sodium citrate to the solution and stir until completely dissolved;

[0010] (2) Add excess NaOH solution to the solution obtained in step (1), stir, and a dark blue Cu(OH)2 suspension is obtained;

[0011] (3) Add ascorbic acid to the Cu(OH)2 suspension obtained in step (2), stir, and age to obtain an orange-red suspension. Perform solid-liquid separation, wash the precipitate with deionized water, and vacuum dry to obtain orange-red powder Cu2O.

[0012] (4) Disperse the Cu2O powder obtained in step (3) into ultrapure water and add antimony salt. The molar ratio of Cu2O to Sb is (1.25-1.75):1. After ultrasonic dispersion, add excess thioacetamide (TAA) to the suspension and stir continuously. Then place the suspension in a high-pressure reactor and keep it at 130-190℃ for 10-24 hours.

[0013] (5) After cooling the suspension obtained in step (4) to room temperature, filter, wash, and vacuum dry to obtain Cu3SbS4 nanoparticles.

[0014] Preferably, the copper salt is CuSO4, CuCl2 or Cu(Ac)2, with CuSO4 being the most preferred.

[0015] Preferably, the antimony salt is Sb(Ac)3 or SbCl3, with Sb(Ac)3 being preferred.

[0016] Preferably, the stirring time in step (1) is 5-30 min, preferably 10-20 min.

[0017] Preferably, the stirring time in step (2) is 5-30 min, preferably 10-20 min.

[0018] Preferably, the stirring time in step (3) is 1-10 min, preferably 3-5 min.

[0019] Preferably, the aging time in step (3) is 0.5-3 hours.

[0020] Preferably, the vacuum drying temperature is 50-70℃, and the vacuum drying time is 3-16 hours.

[0021] Preferably, the molar ratio of Cu2O to Sb in step (4) is 1.5:1.

[0022] Preferably, the ultrasonic dispersion time in step (4) is 10-30 min, preferably 15 min, and the ultrasonic frequency is 35-40 kHz.

[0023] Preferably, in step (4), after adding excess thioacetamide, the mixture is stirred continuously for 20-60 minutes.

[0024] Preferably, step (4) involves maintaining the temperature at 180°C for 12 hours.

[0025] This invention also provides the application of Cu3SbS4 nanoparticles prepared by the above method in electrocatalytic carbon dioxide reduction.

[0026] Cu3SbS4 is a material with high thermal stability and is commonly used to make thermoelectric devices. In this invention, it is used as a catalyst, preferably, for the electrocatalytic reduction of carbon dioxide to produce CO.

[0027] Cu3SbS4 nanoparticles alter the catalyst's adsorption capacity for reaction intermediates through the strong electronic interaction between Cu and Sb elements, causing the catalyst's selectivity to shift between HCOOH and CO, ultimately improving the catalyst's selectivity for C1 products.

[0028] The sulfide catalyst provided by this invention has high conductivity and reduces the CO2RR overpotential. The results show that its CO2RR process is a 2-electron catalytic mechanism, which is a relatively ideal CO2RR reaction process.

[0029] Beneficial effects:

[0030] (1) The Cu3SbS4 nanoparticles for electrocatalytic carbon dioxide reduction provided by the present invention are applied to electrocatalytic CO2RR. Compared with Sb2S3, they have significant property improvement, compared with CuS, they have significant selective regulation, have high C1 selectivity, and have excellent stability.

[0031] (2) The electrocatalytic carbon dioxide reduction catalyst prepared in this invention is a sulfide catalyst, which has unique properties and high electronic conductivity compared with oxides, and can effectively reduce overpotential.

[0032] (3) This invention uses CuSO4, sodium citrate, NaOH, ascorbic acid, Sb(Ac)3 and thioacetamide as raw materials to first synthesize Cu2O nanocubic particles, and then synthesize Cu3SbS4 nanoparticles by hydrothermal synthesis. The synthesis method is simple, does not use organic solvents, and the reaction conditions are mild and easy to achieve, which is conducive to industrial promotion. Attached Figure Description

[0033] Figure 1 The XRD patterns of Cu3SbS4 nanoparticles from Examples 1-3 are shown.

[0034] Figure 2 Here is a SEM image of Cu3SbS4 nanoparticles from Example 1.

[0035] Figure 3 The catalyst Cu3SbS4 nanoparticles of Example 1 were subjected to oxidation at 50 mA / cm² in a CO2 atmosphere. -2 Stability testing;

[0036] Figure 4 This is a comparison of the selectivity of Cu3SbS4 nanoparticles, the catalyst of Example 1, with CuS and Sb2S3 for CO. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to specific embodiments.

[0038] Example 1:

[0039] A method for preparing Cu3SbS4 nanoparticles, comprising the following steps:

[0040] The first step involved dissolving 84.4 mg of CuSO4·5H2O and 36.75 mg of sodium citrate in 20 ml of H2O and stirring continuously for 15 min. The second step involved adding 5 ml of 1.25 M NaOH dropwise to the mixture and stirring continuously for another 15 min to obtain a deep blue Cu(OH)2 suspension. The third step involved adding 12.5 ml of 0.03 M ascorbic acid dropwise to the solution. After stirring for three minutes, the mixture was aged for 1 h. The suspension was then filtered, washed three times with deionized water, and finally vacuum dried at 60 °C to obtain an orange-red Cu2O precursor. The fourth step involved adding the obtained Cu2O and antimony acetate in a molar ratio of Cu2O:Sb(Ac)3 = 1.5:1 to 10 ml of a solution, followed by the addition of 150 mg of thioacetamide. After thorough dispersion, the mixture was hydrothermally heated at 180 °C for 12 h. The fifth step involved allowing the mixture to cool naturally, washing with water three times, filtering, and then vacuum drying at 60 °C. The products were collected.

[0041] Example 2

[0042] Based on Example 1, the molar ratio of Cu2O to Sb(Ac)3 in step 4 was adjusted to 1.25:1, while other conditions remained unchanged, to prepare Cu3SbS4 nanoparticles.

[0043] Example 3

[0044] Based on Example 1, the molar ratio of Cu2O to Sb(Ac)3 in step 4 was adjusted to 1.75:1, while other conditions remained unchanged, to prepare Cu3SbS4 nanoparticles.

[0045] 1. Morphology of Cu3SbS4 nanoparticles

[0046] The morphology of the Cu3SbS4 nanoparticles prepared in Example 1 was observed under an electron microscope, as follows: Figure 2 As shown, it is cubic in shape, with a size of approximately 50 nm, and is uniform in size.

[0047] 2. Electrochemical performance

[0048] Preparation of the working electrode:

[0049] Weigh 1 mg of catalyst and add it to 30 μL of ethanol and 10 μL of Nafion solution. After ultrasonic dispersion for 30 min, coat the ink evenly onto hydrophobic carbon paper with an area of ​​2 cm * 0.5 cm. After natural drying, perform electrochemical tests.

[0050] Electrochemical testing:

[0051] The test used a standard three-electrode system, conducted in a flow cell on an electrochemical workstation (CS2350H). The counter electrode was a platinum sheet, and the reference electrode was an Ag / AgCl electrode. Both the cathodic and anolyte used 30 mL of 0.5 MkHCO3 solution. Before the test, CO2 was purged for 10 min to remove air from the pipeline, and the CO2 flow rate was maintained at 20 sccm during the test. Gaseous products were quantitatively analyzed by gas chromatography, and liquid products were quantitatively analyzed by nuclear magnetic resonance (NMR). Figure 4 As shown, among the three sulfide catalysts, the Cu3SbS4 nanoparticles prepared in this invention exhibit significantly higher selectivity for CO than CuS and Sb2S3.

[0052] like Figure 3 As shown, in the stability test, the catalyst was kept at a current density of 50 mA / cm². -2 Its selectivity for CO remains stable within 60 hours.

[0053] The Zn₂SnO₄ / ZnO nanosheets prepared in Examples 1-3 were characterized by X-ray diffraction (XRD), and the results are as follows: Figure 1 As shown, Cu3SbS4 nanoparticles can be obtained when the molar ratio of Cu2O to Sb(Ac)3 is in the range of (1.25-1.75):1.

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing Cu3SbS4 nanoparticles, characterized in that, Includes the following steps: (1) At room temperature, dissolve the copper salt in ultrapure water, then add sodium citrate to the solution and stir until completely dissolved; (2) Add excess NaOH solution to the solution obtained in step (1), stir, and a dark blue Cu(OH)2 suspension is obtained; (3) Add ascorbic acid to the Cu(OH)2 suspension obtained in step (2), stir, and age to obtain an orange-red suspension. Perform solid-liquid separation, wash the precipitate with deionized water, and vacuum dry to obtain orange-red powder Cu2O. (4) Disperse the Cu2O powder obtained in step (3) into ultrapure water and add antimony salt. The molar ratio of Cu2O to Sb is (1.25-1.75):

1. After ultrasonic dispersion, add excess thioacetamide to the suspension and stir continuously. Then place the suspension in a high-pressure reactor and keep it at 130-190℃ for 10-24 hours. (5) After cooling the suspension obtained in step (4) to room temperature, filter, wash, and vacuum dry to obtain Cu3SbS4 nanoparticles.

2. The preparation method according to claim 1, characterized in that, The copper salt is CuSO4, CuCl2, or Cu(Ac)2.

3. The preparation method according to claim 1, characterized in that, The antimony salt is Sb(Ac)3 or SbCl3.

4. The preparation method according to claim 1, characterized in that, In step (4), the molar ratio of Cu2O to Sb is 1.5:

1.

5. The preparation method according to claim 1, characterized in that, The aging time in step (3) is 0.5-3 hours.

6. The preparation method according to claim 1, characterized in that, The temperature for vacuum drying is 50-70℃.

7. The preparation method according to claim 1, characterized in that, The ultrasonic dispersion time in step (4) is 10-30 min, and the ultrasonic frequency is 35-40 kHz.

8. The preparation method according to claim 1, characterized in that, Step (4) involves keeping the temperature at 180℃ for 12 hours.

9. The application of Cu3SbS4 nanoparticles prepared according to claim 1 in electrocatalytic carbon dioxide reduction.

10. The application according to claim 9, characterized in that, Used for the electrocatalytic reduction of carbon dioxide to produce CO.

Images