CN115807239A - Cu 3 SbS 4 Preparation method and application of nanoparticles - Google Patents

Abstract

The invention relates to the technical field of new energy materials and electrochemical catalysis. In order to improve the activity and selectivity in the process of reducing and catalyzing carbon dioxide, the invention provides Cu ₃ SbS ₄ The preparation method of the nano-particles comprises the steps of firstly dissolving a certain amount of copper salt in water, adding ascorbic acid for reduction under the action of sodium citrate and sodium hydroxide, aging suspension, carrying out suction filtration and drying to obtain a precursor Cu ₂ O; mixing antimony salt and Cu ₂ Coordinating the O precursor and thioacetamide in an aqueous solution, and placing the suspension in a high-pressure reaction kettle to keep the temperature at 180 ℃ for several hours; after the sample is naturally cooled, washing and drying are carried out to obtain the final Cu ₃ SbS ₄ And (3) nanoparticles. Cu to be prepared by the invention ₃ SbS ₄ For electrocatalysis ofThe carbon oxide is reduced to prepare CO, and the method has high selectivity and high stability for electrocatalytic carbon dioxide reduction.

Description

Preparation method and application of Cu3SbS4 nanoparticles

technical field

The invention belongs to the field of new energy material technology and electrochemical catalysis technology, and in particular relates to a preparation method and application of Cu ₃ SbS ₄ nano particles.

Background technique

Due to the global consumption of fossil fuels, carbon dioxide continues to accumulate in the atmosphere, causing problems such as the greenhouse effect, melting glaciers and ocean acidification. Converting carbon dioxide into valuable chemicals is a possible solution to these problems. There are mainly four implementation methods: photocatalytic _CO2 reduction, biocatalytic _CO2 conversion, thermocatalytic reaction, and electrocatalytic reduction. In recent years, the electrocatalytic _CO2 reduction reaction ( _CO2RR ) has attracted extensive attention. The process potential and reaction temperature are controllable, and by using renewable energy for power, the electrocatalytic reduction of _CO2 to high value-added industrial chemicals has also become economically attractive.

Nowadays, catalysts are mainly divided into four categories according to their ability to bind with intermediates: i) Metals such as In, Sn, Cd, and Bi tend to produce formic acid. ii) Au, Ag, Zn, etc. have strong selectivity to CO. iii) Metals such as Ni, Fe, Pt, and Ti are favorable for the hydrogen evolution reaction in water electrolysis and produce _H2 as a product. iv), copper can bind CO* intermediates well, and the binding energy to H* is relatively weak, so metallic copper is the only one that can convert CO* intermediates to C2 ₊ products (such as hydrocarbons and alcohols) substance. Due to its unique electronic properties, the Cu-based catalyst has a complex selectivity for CO ₂ RR. The electronic control between the two is achieved by doping foreign atoms, which affects its adsorption capacity for reaction intermediates, and is ultimately used to control CO 2 RR. ₂ RR product.

Metal sulfides have broad application prospects in hydrogen evolution reaction, photocatalyst and supercapacitor. And the presence of S atoms can stabilize the CO ₂ ^· -intermediate, thereby promoting CO ₂ electroreduction. It has been reported in the literature that the faradaic efficiency (FE) of Cu ₂ S modified by Cu surface vacancies for n-propanol is 8%; while the selectivity (FE _C2H4 ) of CuO catalysts modified by Sb single atoms to ethylene is 58%, because Sb _The synergistic effect of sites and oxygen vacancies significantly reduces the dimerization energy of the adsorbed CO* reaction intermediates, thereby facilitating the conversion of _CO2 to _C2H4 . Therefore, by doping the catalyst, studying the change of electrocatalytic CO ₂ RR selectivity of the CuS-based catalyst, improving the activity and stability of the catalyst will play an important role in elucidating the change of the reaction mechanism of the catalyst.

Therefore, it has great research prospects and practical significance to realize the improvement of activity and selectivity in the catalytic process of carbon dioxide reduction by adjusting the composition, size and morphology of CuS-based catalysts.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a preparation method and application of Cu ₃ SbS ₄ nanoparticles. The present invention uses copper salt, sodium citrate, NaOH, ascorbic acid, antimony salt and thioacetamide as raw materials to first synthesize Cu ₂ O nanometer cubes, and then synthesize Cu ₃ SbS ₄ nanometer particles through hydrothermal. The obtained Cu ₃ SbS ₄ nanoparticles changed the adsorption capacity of the catalyst to the reaction intermediates through the strong electronic interaction between Cu and Sb elements, which made the selectivity of the catalyst shift between HCOOH and CO, and finally improved the catalyst Selectivity to _C1 products.

The technical scheme that the present invention takes is:

A method for preparing Cu ₃ SbS ₄ nanoparticles, characterized in that it comprises 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) in the solution that obtains in step (1) _, add excess NaOH solution, stir, obtain dark blue Cu (OH) Suspension;

(3) Add ascorbic acid to the Cu(OH) ₂ suspension obtained in step (2), stir, and age to obtain an orange-red suspension, carry out solid-liquid separation, wash the precipitate with deionized water, and vacuum-dry to obtain orange-red suspension. Red powder Cu ₂ O;

(4) Disperse the Cu ₂ O powder obtained in step (3) into ultrapure water, and add antimony salt, the molar ratio of Cu ₂ O to Sb is (1.25-1.75): 1 Add excess thioacetamide (TAA) to the turbid liquid and keep stirring; then place the suspension in an autoclave and keep it warm at 130-190°C for 10-24 hours;

(5) Cool the suspension obtained in step (4) to room temperature, filter, wash, and vacuum-dry to obtain Cu ₃ SbS ₄ nanoparticles.

Preferably, the copper salt is CuSO ₄ , CuCl ₂ or Cu(Ac) ₂ , preferably CuSO ₄ .

Preferably, the antimony salt is Sb(Ac) ₃ or SbCl ₃ , preferably Sb(Ac) ₃ .

Preferably, the stirring time of the step (1) is 5-30 min, preferably 10-20 min.

Preferably, the stirring time of the step (2) is 5-30 min, preferably 10-20 min.

Preferably, the stirring time of the step (3) is 1-10 min, preferably 3-5 min.

Preferably, the aging time in the step (3) is 0.5-3h.

Preferably, the vacuum drying temperature is 50-70°C. Vacuum drying time is 3-16h.

Preferably, the molar ratio of Cu ₂ O to Sb in the step (4) is 1.5:1.

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

As a preference, the step (4) is continuously stirred for 20-60 min after adding excess thioacetamide.

As a preference, the step (4) is incubated at 180° C. for 12 hours.

The present invention also provides the application of Cu ₃ SbS ₄ nanoparticles prepared by the above method in electrocatalytic carbon dioxide reduction.

Cu ₃ SbS ₄ is a material with high thermal stability and is usually used to make thermoelectric devices. The present invention uses it as a catalyst, preferably for electrocatalytic reduction of carbon dioxide to prepare CO.

The Cu ₃ SbS ₄ nanoparticles change the adsorption capacity of the catalyst to the reaction intermediates through the strong electronic interaction between Cu and Sb elements, so that the selectivity of the catalyst changes between HCOOH and CO, and finally enhances the catalyst’s ability to adsorb C ₁ Product selectivity.

The sulfide catalyst provided by the invention has high electrical conductivity and reduces the overpotential of CO ₂ RR. The result shows that the CO ₂ RR process is a 2-electron catalytic mechanism, which is an ideal CO ₂ RR reaction process.

Beneficial effect:

(1) The Cu ₃ SbS ₄ nanoparticles for electrocatalytic carbon dioxide reduction provided by the present invention are applied to electrocatalytic CO ₂ RR, which has obvious property improvement compared with Sb ₂ S ₃ , and has obvious selective regulation compared with CuS , with high _C1 selectivity and excellent stability.

(2) The electrocatalytic carbon dioxide reduction catalyst prepared by the present invention is a sulfide catalyst, which has unique properties compared with oxides, and high electronic conductivity, which can effectively reduce the overpotential.

(3) The present invention uses CuSO ₄ , sodium citrate, NaOH, ascorbic acid, Sb(Ac) ₃ and thioacetamide as raw materials to first synthesize Cu ₂ O nanocubes, and then synthesize Cu ₃ SbS ₄ nanoparticles by hydrothermal , the synthesis method is simple, no organic solvent is used, the reaction condition is mild, and it is easy to realize, which is beneficial to industrial promotion.

Description of drawings

Fig. 1 is the XRD pattern of Cu ₃ SbS ₄ nanoparticles of embodiment 1-3;

Fig. 2 is the SEM picture of the Cu ₃ SbS ₄ nanoparticles of embodiment 1;

Fig. 3 is the catalyst Cu of embodiment 1 ₃ SbS ₄ nanoparticles in CO Atmosphere in the stability test of 50mAcm ^-2 _;

Fig. 4 is a comparison diagram of the selectivity of the catalyst Cu ₃ SbS ₄ nanoparticles, CuS and Sb ₂ S ₃ to CO in Example 1.

Detailed ways

The present invention will be described in further detail below in conjunction with specific embodiments.

Example 1:

A preparation method of Cu ₃ SbS ₄ nanoparticles, the steps are as follows:

In the first step, 84.4mg CuSO ₄ 5H ₂ O and 36.75mg sodium citrate were dissolved in 20ml H ₂ O and kept stirring for 15min. In the second step, 5ml of 1.25M NaOH was added dropwise to the mixed solution, and the stirring was continued for 15min to obtain a dark blue Cu(OH) ₂ suspension. In the third step, 12.5ml of 0.03M ascorbic acid was added dropwise to the solution. After stirring for three minutes, it was aged for 1 hour. Afterwards, the suspension was suction-filtered, washed three times with deionized water, and finally vacuum-dried at 60° C. to obtain an orange-red Cu ₂ O precursor. The fourth step is to add the obtained Cu ₂ O and antimony acetate in a molar ratio of Cu ₂ O:Sb(Ac) ₃ =1.5:1 to 10ml of the solution, and then add 150mg of thioacetamide. Under water heat 12h. In the fifth step, after natural cooling, wash with water and suction filter three times, and vacuum-dry at 60°C. The product was collected.

Example 2

On the basis of Example 1, the molar ratio of Cu ₂ O and Sb(Ac) ₃ in the fourth step was adjusted to 1.25:1, and other conditions remained unchanged, to prepare Cu ₃ SbS ₄ nanoparticles.

Example 3

On the basis of Example 1, the molar ratio of Cu ₂ O and Sb(Ac) ₃ in the fourth step was adjusted to 1.75:1, and other conditions remained unchanged, to prepare Cu ₃ SbS ₄ nanoparticles.

1. Morphology of Cu ₃ SbS ₄ nanoparticles

The morphology of the Cu ₃ SbS ₄ nanoparticles prepared in Example 1 was observed under an electron microscope. As shown in FIG. 2 , they were cube-shaped, about 50 nm in size, and uniform in size.

2. Electrochemical properties

Preparation of working electrode:

Weigh 1 mg of the catalyst and add it to 30 μL ethanol and 10 μL Nafion solution. After ultrasonic dispersion for 30 minutes, the ink is evenly applied to the hydrophobic carbon paper with an area of 2 cm*0.5 cm. After natural drying, the electrochemical test is carried out.

Electrochemical test:

The test uses a standard three-electrode system, and uses a flow cell to test on an electrochemical workstation (CS2350H). The counter electrode is a platinum sheet, and the reference electrode is an Ag/AgCl electrode. Both catholyte and anolyte used 30 mL of 0.5M _KHCO3 solution. Before the test, pass CO ₂ for 10 minutes to remove the air in the pipeline, and keep the CO ₂ flow rate at 20 sccm during the test. Gas products are quantitatively analyzed by gas chromatography, and liquid products are quantitatively analyzed by NMR. As shown in Figure 4, among the three sulfide catalysts, the selectivity of Cu ₃ SbS ₄ nanoparticles prepared by the present invention to CO is significantly higher than that of CuS and Sb ₂ S ₃ .

As shown in Figure 3, in the stability test, the catalyst was kept at a current density of 50 mAcm ^-2 , and its selectivity to CO remained stable within 60 hours.

The Zn ₂ SnO ₄ /ZnO nanosheets prepared in Example 1-3 were characterized by X-ray diffraction (XRD), and the results are shown in Figure 1, showing that Cu ₂ O and Sb(Ac) ₃ molar ratio in (1.25 -1.75): Cu ₃ SbS ₄ nanoparticles can be obtained within the range of 1.

The above-mentioned embodiments are only descriptions of preferred implementations of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (10)

1. Cu ₃ SbS ₄ The preparation method of the nano-particles is characterized by comprising the following steps:

(1) Dissolving a copper salt into ultrapure water at room temperature, adding sodium citrate into the solution, and stirring until the sodium citrate is completely dissolved;

(2) Adding into the solution obtained in the step (1)Excess NaOH solution, stirring, to give a deep blue Cu (OH) ₂ Suspending liquid;

(3) Adding Cu (OH) obtained in the step (2) ₂ Adding ascorbic acid into the suspension, stirring, aging to obtain orange suspension, performing solid-liquid separation, washing the precipitate with deionized water, and vacuum drying to obtain orange powder Cu ₂ O；

(4) The Cu obtained in the step (3) ₂ Dispersing O powder into ultrapure water, and adding antimony salt and Cu ₂ The molar ratio of O to Sb is (1.25-1.75) 1, adding excessive thioacetamide into the suspension after uniform ultrasonic dispersion, and continuously stirring; then placing the suspension into a high-pressure reaction kettle, and preserving the heat for 10-24 hours at the temperature of 130-190 ℃;

(5) Cooling the suspension obtained in the step (4) to room temperature, filtering, washing and drying in vacuum to obtain Cu ₃ SbS ₄ And (3) nanoparticles.

2. The method according to claim 1, wherein the copper salt is CuSO ₄ 、CuCl ₂ Or Cu (Ac) ₂ 。

3. The method according to claim 1, wherein the antimony salt is Sb (Ac) ₃ Or SbCl ₃ 。

4. The method according to claim 1, wherein the step (4) of Cu ₂ The molar ratio of O to Sb was 1.5.

5. The method according to claim 1, wherein the aging time in the step (3) is 0.5 to 3 hours.

6. The method according to claim 1, wherein the temperature of the vacuum drying is 50 to 70 ℃.

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

8. The method according to claim 1, wherein the step (4) is performed at 180 ℃ for 12 hours.

9. Cu prepared according to claim 1 ₃ SbS ₄ Use of nanoparticles in electrocatalytic carbon dioxide reduction.

10. Use according to claim 7 for the electrocatalytic reduction of carbon dioxide to produce CO.

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