Preparation method and application of ZnxCd1-xS nano-catalyst rich in sulfur vacancies

Abstract

The invention relates to the technical field of nano-catalysts, and discloses a preparation method and application of a ZnxCd1-xS nano-catalyst rich in sulfur vacancies, the preparation method of the ZnxCd1-xS nano-catalyst rich in sulfur vacancies is characterized by comprising the following steps: S1, mixing cadmium salt, zinc salt and thiourea in deionized water to obtain a mixed solution; and S2, putting the mixed solution into a reaction kettle for heating reaction, cooling, collecting a reaction product, washing the reaction product with deionized water, and drying the washed reaction product to prepare the ZnxCd1-xS nano-catalyst. The ZnxCd1-xS nano-catalyst synthesized by the method is uniform in dispersion, uniform in size and regular in morphology, the morphology of the obtained ZnxCd1-xS nano-catalyst is evolved into a litchi-shaped transition state with a rough surface from a spherical shape along with the rise of the reaction temperature, and then a pine tree-shaped morphology with the regular morphology is generated. In addition, the prepared catalyst is rich in certain sulfur vacancies, and the performance is remarkably improved when the catalyst is applied to the field of photocatalytic hydrogen evolution.

Description

Technical Field

[0001] This invention relates to the field of nanocatalyst technology, and more particularly to Zn rich in sulfur vacancies. x Cd 1-x Preparation methods and applications of S nanocatalysts. Background Technology

[0002] With the continuous development of human society and the increase in population, finite resources such as fossil fuels like coal, oil, and natural gas are insufficient to meet human needs, and the rapid depletion of fossil resources has led to environmental pollution and global climate change. Therefore, finding a sustainable and clean alternative energy source is urgent. Through long-term exploration, hydrogen energy has been discovered to have advantages such as high calorific value, abundant sources, and pollution-free combustion products, and is considered humanity's "ultimate energy source." Currently, industrial hydrogen production methods mainly include water electrolysis, coal chemical hydrogen production, natural gas hydrogen production, methanol steam reforming, and thermochemical water cracking, but these methods are energy-intensive, complex, and produce significant amounts of greenhouse gases. Solar energy, as a precious gift from nature, is inexhaustible. Unfortunately, the inherent intermittency and unpredictability of solar radiation make it difficult to store and use.

[0003] Photocatalytic water splitting for hydrogen production using semiconductors can convert solar energy into chemical energy for storage and utilization, and is considered one of the most promising ways to solve environmental pollution and energy problems. Scientists have invested considerable effort in this research, but the results have been less than satisfactory, mainly due to low efficiency, weak stability, and low yield. Furthermore, the rapid reverse reaction further consumes the already limited hydrogen resources. These factors mean that research on photocatalytic water splitting for hydrogen production remains in the laboratory stage, and achieving industrialization remains a significant challenge. Therefore, developing efficient, stable, and inexpensive photocatalytic materials and systems is of broad and profound significance for solving current environmental and energy problems.

[0004] Metal sulfides have been proven to possess excellent photocatalytic hydrogen evolution performance. The reaction efficiency and stability of photocatalytic hydrogen evolution largely depend on the catalyst's structural characteristics (such as band gap and number of surface active sites) and reaction system conditions. Meanwhile, dynamic changes at the catalyst-reaction interface (such as photogenerated carrier separation efficiency and reduction kinetics) can significantly affect the catalyst's hydrogen evolution activity and cycle life. Therefore, developing novel metal sulfide catalysts with broad spectral response ranges and strong carrier migration capabilities is considered an ideal method to improve the rate and stability of photocatalytic hydrogen evolution. Among these, constructing heterostructures and introducing defect sites in metal sulfide catalysts can broaden the spectral absorption boundary, suppress photogenerated electron-hole pair recombination, and enhance H⁺ adsorption and reduction on the surface, which is crucial for achieving efficient and stable photocatalytic hydrogen evolution. Summary of the Invention

[0005] To solve the technical problems existing in the prior art, the present invention provides a preparation method and application of a Zn x Cd 1-x S nanocatalyst rich in sulfur vacancies.

[0006] The present invention is implemented by the following technical solutions: A preparation method of a Zn x Cd 1-x S nanocatalyst rich in sulfur vacancies, comprising the following steps: Step S1: Mix a cadmium salt, a zinc salt and thiourea in deionized water to obtain a mixed solution; Step S2: Place the mixed solution in a reaction kettle for heating reaction, collect the reaction product after cooling, wash the reaction product with deionized water, and dry the washed reaction product to prepare a Zn x Cd 1-x S nanocatalyst.

[0007] As a further improvement of the above solution, 0 < X < 1 in the Zn x Cd 1-x S nanocatalyst; the molar ratio of cadmium in the cadmium salt, zinc in the zinc salt and thiourea is (this needs to be adjusted according to the actual situation).

[0008] As a further improvement of the above solution, the mixing conditions of the mixed solution in Step S1 are: the temperature of deionized water is 20 - 50 °C, and the stirring time is 0.5 - 1 h.

[0009] As a further improvement of the above solution, the reaction conditions in Step S2 are: the hydrothermal reaction temperature of the reaction kettle is 130 - 200 °C, and the reaction time is 3 - 8 h.

[0010] As a further improvement of the above solution, the drying conditions of the reaction product in Step S2 are: the reaction product is placed in a vacuum drying oven at 40 - 80 °C for drying for 8 - 12 h.

[0011] As a further improvement of the above solution, the washing conditions in Step S2 are: wash successively with deionized water, a mixed solution of deionized water and absolute ethanol in a ratio of 1:1, and absolute ethanol, and centrifuge to collect the solid product after each washing.

[0012] A Zn x Cd 1-x S nanocatalyst rich in sulfur vacancies, and the Zn x Cd 1-x S nanocatalyst is used for photocatalytic hydrogen evolution.

[0013] As a further improvement to the above scheme, the catalytic reaction conditions are as follows: in an argon atmosphere of 4-8 kPa, the solid-liquid reaction mode is used to participate in the photocatalytic reaction.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention uses cadmium and zinc metal salts as raw materials, thiourea as a sulfur source, and deionized water as a solvent. The uniformly stirred solution is transferred to a reaction vessel, and Zn with different morphologies is obtained by changing the temperature of the hydrothermal reaction. x Cd 1-x S nanocatalysts.

[0015] 2. The preparation process of this invention is simple and easy to operate, and takes less time. The prepared nanocatalysts are uniformly dispersed, have uniform size, and regular morphology. Specifically, as the reaction temperature increases, the obtained Zn... x Cd 1-x The morphology of the S nanocatalyst evolves from a spherical shape to a transitional state with a rough, lychee-like surface, and then generates a regular pine-like morphology.

[0016] 3. The nanocatalyst prepared in this invention is rich in sulfur vacancies, and its performance is significantly improved when applied to the field of photocatalytic hydrogen evolution, while also exhibiting good stability; the Zn x Cd 1-x The synthesis method of S nanocatalysts has important application value in large-scale industrial applications. Attached Figure Description

[0017] Figure 1 [A1] refers to the sulfur-vacancy-rich Zn proposed in this invention. x Cd 1-x Flowchart of the preparation method of S nanocatalyst; Figure 2 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x Scanning electron microscope (SEM) images of S nanocatalysts, including: Figure 2 a corresponds to Zn synthesized at a reaction temperature of 130℃. x Cd 1-x Scanning electron microscope image of S nanocatalyst; Figure 2 b corresponds to Zn synthesized at a reaction temperature of 160℃. x Cd 1-x Scanning electron microscope image of S nanocatalyst; Figure 2 c corresponds to the Zn synthesized at a reaction temperature of 180℃. x Cd 1-x Scanning electron microscope image of S nanocatalyst; Figure 2 d corresponds to the Zn synthesized at a reaction temperature of 200℃. x Cd 1-x Scanning electron microscope image of S nanocatalyst; Figure 3 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x High-resolution transmission electron microscopy (HRTEM) image of the S nanocatalyst, which was synthesized at 180 °C for 5 h. Figure 4 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x X-ray diffraction (XRD) pattern of S nanocatalyst, wherein: Figure 4 a corresponds to Zn synthesized at a reaction temperature of 130℃. x Cd 1-x X-ray diffraction (XRD) pattern of S nanocatalyst; Figure 4 b corresponds to Zn synthesized at a reaction temperature of 160℃. x Cd 1-x X-ray diffraction (XRD) pattern of S nanocatalyst; Figure 4 c corresponds to the Zn synthesized at a reaction temperature of 180℃. x Cd 1-x X-ray diffraction (XRD) pattern of S nanocatalyst; Figure 4 d corresponds to the Zn synthesized at a reaction temperature of 200℃. x Cd 1-x X-ray diffraction (XRD) pattern of S nanocatalyst; Figure 5 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x The infrared (FT-IR) spectrum and Raman spectrum of the S nanocatalyst are shown below: Figure 5 a is the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x The Fourier transform infrared (FT-IR) spectrum of the S nanocatalyst.

[0018] Figure 5 b represents the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x Raman spectroscopy of S nanocatalyst.

[0019] Figure 6 The sulfur-vacancy-rich Zn provided by this inventionx Cd 1-x Electron paramagnetic resonance (EPR) image of S nanocatalyst; Figure 7 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x The N2 adsorption-desorption isotherm (BET) and pore size distribution curve of the S nanocatalyst.

[0020] Figure 8 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x X-ray photoelectron spectroscopy (XPS) spectrum of the S nanocatalyst, synthesized at 180℃ for 5 h, wherein: Figure 8 a is the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x XPS full spectrum of S nanocatalyst.

[0021] Figure 8 b represents the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x XPS spectra of Cd3d nanocatalysts.

[0022] Figure 8 c represents the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x XPS spectra of Zn2p nanocatalysts.

[0023] Figure 8 d represents the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x XPS spectrum of S2p nanocatalyst.

[0024] Figure 9 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x The UV-Vis absorption spectrum and photoluminescence (PL) spectrum of the S nanocatalyst are shown below: Figure 9 a is the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x UV-Vis absorption spectrum of S nanocatalyst.

[0025] Figure 9 b represents the sulfur-vacancy-rich Zn provided by this invention. x Cd 1-x Photoluminescence spectrum (PL) of S nanocatalyst.

[0026] Figure 10 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x The band gap diagram of the S nanocatalyst, in which: Figure 10 a corresponds to Zn synthesized at a reaction temperature of 130℃. x Cd 1-x Band gap diagram of S nanocatalyst; Figure 10 b corresponds to Zn synthesized at a reaction temperature of 160℃. x Cd 1-x Band gap diagram of S nanocatalyst; Figure 10 c corresponds to the Zn synthesized at a reaction temperature of 180℃. x Cd 1-x Band gap diagram of S nanocatalyst; Figure 10 d corresponds to the Zn synthesized at a reaction temperature of 200℃. x Cd 1-x Band gap diagram of S nanocatalyst; Figure 11 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x MS (Metrogram) of S nanocatalyst, where: Figure 11 a corresponds to Zn synthesized at a reaction temperature of 130℃. x Cd 1-x MS image of Mott-Schott free radicals of S nanocatalyst; Figure 11 b corresponds to Zn synthesized at a reaction temperature of 160℃. x Cd 1-x MS image of Mott-Schott free radicals of S nanocatalyst; Figure 11 c corresponds to the Zn synthesized at a reaction temperature of 180℃. x Cd 1-x MS image of Mott-Schott free radicals of S nanocatalyst; Figure 11 d corresponds to the Zn synthesized at a reaction temperature of 200℃. x Cd 1-x MS image of Mott-Schott free radicals of S nanocatalyst; Figure 12 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x Electrochemical impedance and photocurrent response of S nanocatalysts; Figure 13The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x Performance diagram of S nanocatalyst, where: Figure 13 Zn synthesized at 130, 160, 180, and 200℃ for 5 hours. x Cd 1-x Yield of S nanocatalyst; Figure 13 b represents the Zn synthesized at 130, 160, 180, and 200℃ for 5 hours. x Cd 1-x Yield plot of S nanocatalyst; Figure 13 c represents the Zn synthesized at 180℃ under different synthesis times (3, 5, 6, and 8 h). x Cd 1-x Yield of S nanocatalyst; Figure 13 d represents the Zn synthesized at 180℃ for different synthesis times (3, 5, 6, and 8 h). x Cd 1-x S nanocatalyst yield diagram; Figure 13 e represents the Zn synthesized at 180℃ for 5 hours. x Cd 1-x Yields of S nanocatalysts at different photocatalytic reaction temperatures (15, 20, 25 and 30 °C); Figure 13 f represents the Zn synthesized at 180℃ for 5 hours. x Cd 1-x Yield graph of S nanocatalyst at different photocatalytic reaction temperatures (15, 20, 25 and 30 °C); Figure 13 The sulfur-vacancy-rich Zn provided by this invention x Cd 1-x Band structure diagram of S nanocatalyst. Detailed Implementation

[0027] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0028] Example 1

[0029] Zn rich in sulfur vacancies x Cd 1-x The preparation method of S nanocatalyst includes the following steps: Step S1: Mix cadmium salt, zinc salt and thiourea in deionized water to obtain a mixed solution; Step S2: Place the mixed solution in a reaction kettle, heat and react, collect the reaction product after cooling, wash the reaction product with deionized water, and dry the washed reaction product to prepare a Zn x Cd 1-x S nanocatalyst.

[0030] In the Zn x Cd 1-x S nanocatalyst, 0 < X < 1; the molar ratio of cadmium in the cadmium salt, zinc in the zinc salt and thiourea is (this needs to be adjusted according to the actual situation).

[0031] The mixing conditions of the mixed solution in Step S1 are: the temperature of deionized water is 20 - 50 °C, and the stirring time is 0.5 - 1 h.

[0032] The reaction conditions in Step S2 are: the hydrothermal reaction temperature of the reaction kettle is 130 - 200 °C, and the reaction time is 3 - 8 h.

[0033] The drying conditions of the reaction product in Step S2 are: the reaction product is dried in a vacuum drying oven at 40 - 80 °C for 8 - 12 h.

[0034] The washing conditions in Step S2 are: wash successively with deionized water, a mixed solution of deionized water and absolute ethanol in a ratio of 1:1, and absolute ethanol, and collect the solid product by centrifugation after each washing.

[0035] Example 2

[0036] A Zn x Cd 1-x S nanocatalyst rich in sulfur vacancies, and the Zn x Cd 1-x S nanocatalyst is used for photocatalytic hydrogen evolution.

[0037] The catalytic reaction conditions are: an argon atmosphere of 4 - 8 Kpa, and participate in the photocatalytic reaction using a solid-liquid reaction mode.

[0038] Example 3

[0039] As Figure 14 shown, a preparation method of a Zn x Cd 1-x S nanocatalyst rich in sulfur vacancies, which includes the following steps: Step 1: Pour 0.1 mmol of cadmium nitrate tetrahydrate, 0.1 mmol of zinc nitrate hexahydrate and 0.3 mmol of thiourea into a 50 ml beaker containing 20 ml of deionized water in sequence, and stir well for 60 minutes; Step 2: Pour the mixed solution prepared in Step 1 into a 50ml polyethylene reactor. Set the hydrothermal reaction temperature to 180℃ and the reaction time to 5h. After the reactor cools naturally, collect the orange-yellow product, wash it three times each with deionized water, anhydrous ethanol, and a mixture of the two, and then dry it in a vacuum drying oven at 60℃ for 12h to obtain Zn. x Cd 1-x S nanocatalysts.

[0040] Example 4

[0041] like Figure 1 As shown, a Zn rich in sulfur vacancies x Cd 1-x The preparation method of S nanocatalyst includes the following steps: Step 1: Pour 0.1 mmol cadmium chloride dihydrate, 0.1 mmol zinc chloride hexahydrate and 0.3 mmol thiourea into a 50 ml beaker containing 20 ml deionized water and stir thoroughly for 60 minutes. Step 2: Pour the mixed solution prepared in Step 1 into a 50ml polyethylene reactor. Set the hydrothermal reaction temperature to 180℃ and the reaction time to 5h. After the reactor cools naturally, collect the orange-yellow product, wash it three times each with deionized water, anhydrous ethanol, and a mixture of the two, and then dry it in a vacuum drying oven at 60℃ for 12h to obtain Zn. x Cd 1-x S nanocatalysts.

[0042] Example 5

[0043] like Figure 1 As shown, a Zn rich in sulfur vacancies x Cd 1-x The preparation method of S nanocatalyst includes the following steps: Step 1: Pour 0.1 mmol cadmium acetate dihydrate, 0.1 mmol zinc acetate dihydrate and 0.3 mmol thiourea into a 50 ml beaker containing 20 ml deionized water and stir thoroughly for 60 minutes. Step 2: Pour the mixed solution prepared in Step 1 into a 50ml polyethylene reactor. Set the hydrothermal reaction temperature to 180℃ and the reaction time to 5h. After the reactor cools naturally, collect the orange-yellow product, wash it three times each with deionized water, anhydrous ethanol, and a mixture of the two, and then dry it in a vacuum drying oven at 60℃ for 12h to obtain Zn. x Cd 1-x S nanocatalysts.

[0044] Example 6

[0045] like Figure 1As shown, a Zn rich in sulfur vacancies x Cd 1-x The preparation method of S nanocatalyst includes the following steps: Step 1: Pour 0.1 mmol cadmium nitrate tetrahydrate, 0.1 mmol zinc nitrate hexahydrate and 0.3 mmol thioacetamide into a 50 ml beaker containing 20 ml deionized water and stir thoroughly for 60 minutes. Step 2: Pour the mixed solution prepared in Step 1 into a 50ml polyethylene reactor. Set the hydrothermal reaction temperature to 180℃ and the reaction time to 5h. After the reactor cools naturally, collect the orange-yellow product, wash it three times each with deionized water, anhydrous ethanol, and a mixture of the two, and then dry it in a vacuum drying oven at 60℃ for 12h to obtain Zn. x Cd 1-x S nanocatalysts.

[0046] Experimental Example 1: The Zn prepared in Example 3 x Cd 1-x S-meter catalysts are used in photocatalytic hydrogen evolution testing.

[0047] The testing steps are as follows: Weigh out 30mg of Zn x Cd 1-x S nanocatalyst was dispersed in 100 ml of a mixed aqueous solution of 0.25 M sodium sulfide nonahydrate and 0.35 M anhydrous sodium sulfite, and ultrasonically dispersed for 30 min to obtain a uniformly mixed solution A; The photocatalytic reactor was built on the Pofil all-glass automatic online trace gas analysis system. The condenser was connected, and solution A was poured into the photocatalytic reactor. A magnetic stirrer was placed at the bottom of the reactor, and a magnetic magnet was placed inside the reactor. The glass cover of the reactor was clamped and a vacuum was drawn for 30-60 minutes to remove oxygen from the solution. Set the Pofil all-glass automatic online trace gas analysis system to system circulation mode, inject 20ml of argon gas into the reactor using a 20ml syringe, and turn on the system stirring. The hydrogen generator, air generator, and chromatography system were turned on, along with the system circulation and xenon lamp. During testing, the peak area of ​​hydrogen gas was detected using a TCD sensor, and this data was combined with a hydrogen standard curve to determine the photocatalytic hydrogen evolution performance of the nanocatalyst.

[0048] Experimental Example 2: The implementation steps are the same as in Experimental Example 1, except that the Zn prepared in Example 4 is used. x Cd 1-x The S nanocatalyst was tested, and the results obtained were close to those obtained in Experiment 1.

[0049] Experimental Example 3: The implementation steps are the same as in Experimental Example 1, except that the Zn prepared in Example 5 is used. x Cd 1-x The S nanocatalyst was tested, and the results obtained were close to those obtained in Experiment 1.

[0050] Experimental Example 4: The implementation steps are the same as in Experimental Example 1, except that the Zn prepared in Example 6 is used. x Cd 1-x The S nanocatalyst was tested, and the results obtained were close to those obtained in Experiment 1.

[0051] like Figure 1 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x Scanning electron microscope (SEM) image of S nanocatalyst; where Figure 2 a, Figure 2 b、 Figure 2 c and Figure 2 d corresponds to the Zn synthesized at reaction temperatures of 130, 160, 180, and 200 °C, respectively. x Cd 1-x Scanning electron microscope images of Zn nanocatalysts; the prepared Zn nanocatalysts show an increase in reaction temperature. x Cd 1-x The morphology of the S nanocatalyst evolves from a spherical shape to a transitional state with a rough, lychee-like surface, and then generates a regular pine-like morphology.

[0052] like Figure 2 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x High-resolution transmission electron microscopy (HRTEM) image of the S nanocatalyst, synthesized at 180 °C for 5 h. Figure 3 a, Figure 3 As shown in b, the catalyst exhibits a uniformly dispersed, uniformly sized, and regularly shaped pine-tree-like morphology; Figure 3 c. Figure 3 d and Figure 3 e, we can obtain that its lattice spacing is 0.257 nm; Figure 3 f is the selected electron diffraction pattern; Figure 3 g、 Figure 3 h、 Figure 3 i and Figure 3 j shows a uniform distribution of Zn, Cd, and S elements.

[0053] like Figure 3 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-xX-ray diffraction (XRD) pattern of S nanocatalyst; where Figure 4 a, Figure 4 b、 Figure 4 c and Figure 4 d corresponds to the Zn synthesized at reaction temperatures of 130, 160, 180, and 200 °C, respectively. x Cd 1- x X-ray diffraction pattern of S nanocatalyst.

[0054] like Figure 4 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x The Fourier transform infrared (FT-IR) spectrum and Raman spectrum of the S nanocatalyst. Figure 5 a is the Fourier Transmission Spectrum (FT-IR) plot. Figure 5 b is the Raman diagram; as shown Figure 5 As shown in b, 207 cm⁻¹ corresponds to Zn-S bonds, and 296 and 592 cm⁻¹ correspond to Cd-S bonds, further indicating that the prepared catalyst is not a physical mixture of ZnS and CdS, but rather a one-step hydrothermal synthesis of ZnS. x Cd 1-x S solid solution.

[0055] like Figure 5 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x Electron paramagnetic resonance (EPR) image of Zn nanocatalyst. x Cd 1-x S nanocatalysts are rich in sulfur vacancies.

[0056] like Figure 6 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x The N2 adsorption-desorption isotherm (BET) diagram and pore size distribution curve of the S nanocatalyst were obtained. The catalyst was synthesized at 180℃ for 5 h. The catalyst has a specific surface area of ​​3.29 m2 / g and the pore size is concentrated at 20 nm.

[0057] like Figure 7 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x X-ray photoelectron spectroscopy (XPS) spectrum of the S nanocatalyst; the catalyst was synthesized at 180℃ for 5 h, among which... Figure 8 a is the XPS full spectrum. Figure 8 b is the XPS spectrum of Cd3d. Figure 8 c is the XPS spectrum of Zn2p. Figure 8 d is the XPS spectrum of S2p.

[0058] like Figure 8 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x The UV-Vis absorption spectrum and photoluminescence (PL) spectrum of the S nanocatalyst are shown below. Figure 9 a is the ultraviolet-visible absorption spectrum. Figure 9 b is the photoluminescence (PL) spectrum. According to... Figure 9 a shows that Zn synthesized under the condition of 180℃ for 5h x Cd 1-x S nanocatalysts have the best light absorption performance, according to Figure 9 b shows that Zn synthesized under the condition of 180℃ for 5h x Cd 1-x S nanocatalysts achieve the highest separation efficiency of photogenerated carriers.

[0059] like Figure 9 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x Band gap diagram of S nanocatalyst, in which Figure 10 a, Figure 10 b、 Figure 10 c and Figure 10 Figure d corresponds to Zn synthesized at reaction temperatures of 130, 160, 180, and 200 °C, respectively. x Cd 1- x The band gap diagram of the S nanocatalyst shows that the Zn synthesized at 180℃ for 5 h... x Cd 1-x The S nanocatalyst has the smallest band gap, which is beneficial for photocatalytic hydrogen evolution.

[0060] like Figure 10 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x MS image of S nanocatalyst, in which Figure 11 a, Figure 11 b、 Figure 11 c and Figure 11 d corresponds to the Zn synthesized at reaction temperatures of 130, 160, 180, and 200 °C, respectively. x Cd 1-x The Mott-Schott radical (MS) plot of the S nanocatalyst can prove that Zn x Cd 1-x S nanocatalysts are n-type semiconductors and can also be used to plot Zn. x Cd 1-xBand structure diagram of S nanocatalyst.

[0061] like Figure 11 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x Electrochemical impedance and photocurrent response diagrams of S nanocatalysts. Figure 12 a is the electrochemical impedance spectroscopy. Figure 12 b is the photocurrent response diagram, which shows that Zn synthesized at 180℃ for 5 hours... x Cd 1-x S nanocatalysts exhibit the highest photogenerated carrier transport efficiency.

[0062] like Figure 12 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x Performance diagram of S nanocatalyst, among which Figure 13 a, Figure 13 b represents the Zn synthesized under conditions of 130, 160, 180, and 200℃ for 5 hours, respectively. x Cd 1-x The yield and production figures of the S nanocatalyst show that the catalyst synthesized at 180℃ for 5 h exhibits the best performance, with a yield of 5.29 mmol·g. -1 ·h -1 ; Figure 13 c. Figure 13 d represents the Zn synthesized at 180℃ for different synthesis times (3, 5, 6, and 8 h). x Cd 1-x The yield and production figures of the S nanocatalyst show that the catalyst synthesized at 180℃ for 5 h exhibits the best performance, with a yield of 5.29 mmol·g. -1 ·h -1 ; Figure 13 e Figure 13 f represents the Zn synthesized at 180℃ for 5 hours. x Cd 1-x The graphs showing the yield and productivity of the S nanocatalyst at different photocatalytic reaction temperatures (15, 20, 25, and 30 °C) indicate that the catalyst exhibits the best performance at a reaction temperature of 30 °C, achieving a yield of 6.79 mmol·g. -1 ·h -1 .

[0063] like Figure 13 Figure 14 As shown, the prepared Zn is rich in sulfur vacancies. x Cd 1-x Band structure diagram of S nanocatalyst.

[0064] This invention uses cadmium and zinc metal salts as raw materials, thiourea as a sulfur source, and deionized water as a solvent. The uniformly stirred solution is transferred to a reaction vessel, and Zn with different morphologies is obtained by changing the temperature of the hydrothermal reaction. x Cd 1-x S nanocatalysts; the preparation process is simple and easy to operate, with a short time consumption. The prepared nanocatalysts are uniformly dispersed, have uniform size, and regular morphology. Specifically, with increasing reaction temperature, the obtained Zn... x Cd 1-x The morphology of the S nanocatalyst evolves from a spherical shape to a rough, lychee-like transitional state, and then to a regular pine-tree-like morphology. Furthermore, the prepared nanocatalyst is rich in sulfur vacancies, showing significant performance improvement and good stability in the field of photocatalytic hydrogen evolution. This Zn... x Cd 1-x The synthesis method of S nanocatalysts has important application value in large-scale industrial applications.

[0065] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. Zn rich in sulfur vacancies x Cd 1-x A method for producing a S nanocatalyst, characterized by, The method comprises the following steps: S1, mixing cadmium salt, zinc salt and thiourea in deionized water to obtain a mixed solution; Step S2, the mixed solution is placed into a reaction kettle for heating reaction, and the reaction product is collected after cooling. The reaction product is washed with deionized water, and the washed reaction product is dried to prepare Zn x Cd 1-x S nanocatalyst.

2. The Zn x Cd 1-x S nanocatalyst according to claim 1, characterized in that, The Zn x Cd 1-x 0 < X < 1 in the S nanocatalyst; the molar ratio of cadmium in the cadmium salt, zinc in the zinc salt, and thiourea (this needs to be adjusted according to the actual situation).

3. The Zn x Cd 1-x S nanocatalyst according to claim 1, characterized in that, The mixing condition of the mixed solution in the step S1 is that the temperature of the deionized water is 20-50 DEG C, and the stirring time is 0.5-1 h.

4. The Zn x Cd 1-x S nanocatalyst according to claim 1, characterized in that, The reaction condition in the step S2 is that the hydrothermal reaction temperature of the reaction kettle is 130-200 DEG C, and the reaction time is 3-8 h.

5. The Zn x Cd 1-x S nanocatalyst according to claim 1, characterized in that, The drying condition of the reaction product in the step S2 is that the reaction product is placed in a vacuum drying box at 40-80 DEG C for drying for 8-12 h.

6. The Zn x Cd 1-x S nanocatalyst according to claim 1, wherein the Zn The washing condition in the step S2 is that the reaction product is sequentially washed with deionized water, a mixture of deionized water and anhydrous ethanol at a ratio of 1:1 and anhydrous ethanol, and the solid product is collected after each washing by centrifugation.

7. The Zn x Cd 1-x S nanocatalyst according to any one of claims 1 to 6, wherein the Zn x Cd 1-x S nanocatalyst is characterized in that, The Zn x Cd 1-x S nanocatalysts for photocatalytic hydrogen evolution.

8. The Zn rich in sulfur vacancy of claim 7 x Cd 1-x S nanocatalyst characterized in that, The catalytic reaction condition is that the argon atmosphere is 4-8 Kpa, and the solid-liquid reaction mode is used to participate in the photocatalytic reaction.

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