Carbon nano tube loaded tantalum monatomic doped bismuth sulfide catalyst as well as preparation method and application thereof

Abstract

The invention relates to a carbon nanotube loaded tantalum monatomic doped bismuth sulfide catalyst as well as a preparation method and application thereof, and aims to solve the problems that the yield of H2O2 prepared through electro-catalysis of an existing bismuth-based catalyst is relatively low, and the selectivity of H2O2 is relatively low. The preparation method comprises the following steps: 1, dispersing trimesic acid, tantalum pentachloride and bismuth nitrate pentahydrate in methanol, and carrying out solvothermal reaction at 110-140 DEG C to obtain a tantalum-doped bismuth metal organic framework material; 2, grinding and mixing the tantalum-doped bismuth metal organic framework material and dibenzyl disulfide to obtain a mixture; and 3, in an argon atmosphere, heating to 750-950 DEG C, and carrying out heat preservation carbonization treatment. The bismuth sulfide catalyst prepared by the method shows H2O2 selectivity of more than 90% in a wide voltage range of 0-0.65 V, and the H2O2 yield can reach 8.76 mol.g <-1 >. H <-1 > under the industrial-grade current density of 75 mA / cm < 2 >.

Description

Technical Field

[0001] This invention belongs to the field of electrocatalytic materials and nanocomposite materials technology, specifically relating to a method for the two-electron oxygen reduction reaction (2e... - A carbon nanotube-supported bismuth-tantalum sulfide catalyst for the preparation of hydrogen peroxide (ORR), its preparation method, and its application in the electrochemical synthesis of hydrogen peroxide. Background Technology

[0002] Since the beginning of the 21st century, global sustainable development has faced the dual challenges of energy shortages and environmental pollution. Developing green and low-carbon energy conversion technologies and efficient environmental remediation methods has become a core research focus for both academia and industry. Hydrogen peroxide (H2O2), as an important green chemical, possesses both strong oxidizing properties and carbon-free energy carrier characteristics. It has irreplaceable application value in areas such as environmental pollutant degradation, public health disinfection, fine chemical synthesis, and new energy storage. Breakthroughs in its efficient preparation technology are of great significance for promoting the construction of a green manufacturing system.

[0003] In the public health sector, H2O2 has become an important disinfection agent due to its broad-spectrum bactericidal properties and lack of residual pollution, effectively achieving deep sterilization of public places, medical equipment, and environmental surfaces. In the environmental remediation field, advanced oxidation processes (AOPs) based on H2O2 are a core method for treating recalcitrant organic pollutants (such as phenols, polycyclic aromatic hydrocarbons, and pesticide residues). By generating strong oxidizing free radicals such as ·OH, pollutants can be mineralized into CO2 and H2O, significantly improving water purification efficiency.

[0004] In industrial applications, H2O2 replaces traditional chlorine-containing bleaching agents in the paper industry, reducing the emission of toxic pollutants while improving pulp whiteness and fiber strength. In the textile industry, it is used for bleaching and dyeing pretreatment of fabrics, improving dyeing uniformity and reducing wastewater treatment difficulty. In the food industry, it is used as a safe disinfectant for sterilizing packaging materials and preserving food. Especially in the semiconductor manufacturing field, electronic-grade high-purity H2O2 is a key reagent in the chip cleaning and etching process, and its purity directly affects the chip yield and performance, with market demand growing at an average annual rate of over 15%. In the new energy field, H2O2, as an oxidant or liquid fuel for fuel cells, has advantages such as high energy density and clean reaction products, providing new directions for portable energy devices and hydrogen storage.

[0005] Currently, large-scale industrial production of H2O2 mainly relies on the anthraquinone process, which has inherent drawbacks: firstly, the process is complex (including multiple steps such as hydrogenation, oxidation, extraction, and purification), and energy consumption is as high as 1.2-1.5 kWh·kg. -1Furthermore, the production of 1 ton of H2O2 is accompanied by the discharge of approximately 2.5 tons of organic waste liquid, with treatment costs accounting for 15%-20% of the total production cost; secondly, it is highly dependent on Pd precious metal catalysts, with Pd loading reaching 0.3-0.5 wt%, while Pd is scarce (its abundance in the Earth's crust is only 1×10⁻⁶). -6 g·t -1 Firstly, price fluctuations limit production stability; secondly, the product needs to be concentrated from a low concentration of about 5% to 30%-70%, and during the concentration process, H2O2 is prone to decomposition and explosion, posing a serious safety hazard.

[0006] The direct hydrogen-oxygen synthesis method, as an alternative to the anthraquinone process, offers advantages such as high atom economy (theoretical atom utilization of 100%) and a simple reaction pathway. However, it faces dual challenges of safety and efficiency in practical applications. Due to the wide explosion limits of the H2 / O2 mixture (4-94 vol%), more than 50% inert gas (such as N2 or CO2) needs to be introduced for dilution, resulting in a decrease in the effective reactant concentration in the reactor. The H2O2 yield is only 60%-70% of that of the anthraquinone process, and the production cost increases by more than 30%.

[0007] Electrochemical two-electron oxygen reduction reaction (2e - ORR (Organic Reaction Reactor) is considered the most promising H2O2 preparation technology because it can directly convert O2 into H2O2 at room temperature and pressure, offering advantages such as mild reaction conditions, distributed production capability, and environmental friendliness. However, the industrial application of this technology is still limited by three core scientific issues: firstly, the 4e- in the ORR reaction... - Path (generating H2O) and 2e - Competition for pathways leads to a Faraday efficiency of H2O2 generally below 80%; secondly, the high water dissociation energy barrier under alkaline conditions (ΔG > 1.23 eV) results in insufficient proton supply, limiting reaction kinetics; and thirdly, the reaction intermediates... The high desorption energy barrier on the catalyst surface (τ > 10 ms) makes it difficult to increase the yield of H2O2.

[0008] Catalysts are used to regulate 2e - The ORR reaction pathway and performance are central to this process. Existing research indicates that bismuth-based catalysts, due to their suitable O2 adsorption energy, exhibit high performance in the 2e-phase reaction. -ORR exhibits some H2O2 selectivity, but single bismuth-based catalysts suffer from low yields, easy aggregation of active sites, and insufficient stability. Tantalum-based catalysts, on the other hand, possess excellent proton conductivity, promoting water dissociation, but exhibit low H2O2 selectivity when used alone. Although previous studies have attempted simple physical composites of bismuth-based and tantalum-based materials, achieving a balance between high selectivity, high activity, and long-term stability remains challenging. Furthermore, carbon materials, as ideal catalyst supports, possess high conductivity, large specific surface area, and excellent structural stability. However, accurately constructing bimetallic compounds on their surfaces and achieving efficient and stable operation at industrial-grade current densities remains a critical technological bottleneck. Therefore, this invention designs and prepares carbon nanotube-supported bismuth-tantalum sulfide catalysts, aiming to overcome the 2e2 electron dot (2e2) emission limitations through interfacial electronic modulation and structural optimization. - The technical challenges of ORR-based H2O2 production provide new strategies for its industrial application. Summary of the Invention

[0009] The purpose of this invention is to address the problems of low yield in the electrocatalytic preparation of H2O2 by existing bismuth-based catalysts and low selectivity in the electrocatalytic preparation of H2O2 by tantalum-based catalysts, and to provide a carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst, its preparation method, and its application.

[0010] The tantalum single-atom-doped bismuth sulfide catalyst supported on carbon nanotubes of the present invention is prepared by carbonization of tantalum-doped bismuth metal-organic framework material (Ta / CAU-17) and dibenzyl disulfide at a temperature of 750~950℃ under an argon atmosphere; wherein the tantalum-doped bismuth organometallic framework material (Ta / CAU-17) is prepared by solvothermal reaction using pyromellitic acid, tantalum pentachloride and bismuth nitrate pentahydrate as raw materials.

[0011] The microstructure of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst of this invention is a hollow tubular shape.

[0012] The preparation method of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst of the present invention is carried out according to the following steps:

[0013] Step 1: Disperse pyromellitic acid, tantalum pentachloride and bismuth nitrate pentahydrate in methanol and sonicate them. Then transfer them to a high-pressure reactor and carry out a solvothermal reaction at a temperature of 110℃~140℃. After the reaction is completed, collect the solid phase and obtain tantalum-doped bismuth organometallic framework material (Ta / CAU-17) powder after washing and drying.

[0014] Step 2: Grind and mix tantalum-doped bismuth organometallic framework powder and dibenzyl disulfide to obtain a mixture;

[0015] Step 3: Under an argon atmosphere, the mixture is heated to 750~950℃ and carbonized to obtain a carbon nanotube-supported tantalum single-atom doped bismuth sulfide catalyst (Ta-B2S3 / CNT).

[0016] The application of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst of this invention is to use the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst in the two-electron oxygen reduction reaction (2e... - Hydrogen peroxide is prepared in ORR.

[0017] This invention relates to a carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst and its preparation method. This carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst, through precise control of the chemical composition ratio and microstructure, possesses the following key characteristics: First, a synergistic effect is formed between the carbon nanotube support and the bismuth-tantalum sulfide active components, endowing the material with an extremely high specific surface area, providing ample channels for reactant transport; second, the multi-element coordination structure formed by the bismuth and tantalum bimetallic centers and sulfur atoms constructs a high-density active site, significantly enhancing the adsorption and activation capacity for target reactants; furthermore, the excellent conductivity of the carbon nanotubes and the electronic regulation effect of the sulfide heterostructure jointly improve the electronic conductivity of the catalyst, while the bimetallic synergy and the structural support of the carbon support further enhance the stability and cycle durability of the material. Based on these advantages, this catalyst exhibits excellent performance in the electrocatalytic two-electron oxygen reduction reaction (2e⁻¹⁰ ... - In the process of synthesizing hydrogen peroxide (H2O2) by ORR, it exhibits excellent reaction selectivity, catalytic activity and long-term operational stability, effectively overcoming the performance bottleneck of traditional catalysts and providing an efficient and reliable catalytic material system for the green electrosynthesis of H2O2.

[0018] The carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst of the present invention, its preparation method, and its application have the following beneficial effects:

[0019] 1. Structural Innovation: A carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst was successfully prepared using an in-situ growth strategy. This effectively modulated the electronic structure of the active sites, enhancing not only the adsorption capacity for O2 but also promoting the formation of key intermediates. Rapid desorption is achieved, while significantly improving the conductivity and reaction mass transfer efficiency of the material.

[0020] 2. Excellent performance: In 0.1 M KOH electrolyte, this catalyst exhibits H2O2 selectivity exceeding 90% over a wide voltage range of 0–0.65 V (vs. RHE); especially near 0.3 V (vs. RHE), its selectivity approaches 100%. With a high onset potential of 0.66 V, the H2O2 yield reaches 8.76 mol·g at an industrial-grade current density of 75 mA / cm². -1·h -1 It has excellent overall performance.

[0021] 3. Wide range of applications: In addition to being used for efficient electrosynthesis of H2O2, this catalyst can also be coupled with Fenton reaction or organic synthesis processes, showing broad application prospects in the fields of treatment of recalcitrant pollutants and green synthesis of high-value-added chemicals.

[0022] 4. Green and economical preparation process: The entire preparation process does not require precious metals, the raw materials used are readily available and inexpensive, the process flow is short and the conditions are controllable, and it has good repeatability and potential for large-scale production, which is in line with the development direction of green chemical industry. Attached Figure Description

[0023] Figure 1 Scanning electron microscope (SEM) image of the Ta / CAU-17 precursor prepared for the example;

[0024] Figure 2 Scanning electron microscope (SEM) image of the Ta-B2S3 / CNT catalyst prepared for the example;

[0025] Figure 3 Transmission electron microscopy (TEM) image and energy-dispersive X-ray spectroscopy (EDS) image of the Ta-B2S3 / CNT catalyst prepared for the example.

[0026] Figure 4 X-ray photoelectron spectroscopy (XPS) of the Ta-B2S3 / CNT catalyst prepared for the example;

[0027] Figure 5 Linear sweep voltammetry (LSV) curves of Ta-B2S3 / CNT, Bi-SC, and Ta-SC catalysts prepared for the examples;

[0028] Figure 6 The hydrogen peroxide selectivity of the Ta-B2S3 / CNT, Bi-SC, and Ta-SC catalysts prepared in the examples is shown in the diagram.

[0029] Figure 7 The onset potentials of the Ta-B2S3 / CNT, Bi-SC, and Ta-SC catalysts prepared in the examples are shown.

[0030] Figure 8 The Ta-B2S3 / CNT catalyst prepared for the example was tested under constant current density conditions (10 mA / cm²). -2 -90mA / cm -2 The UV-Vis absorption spectrum of the cumulatively generated hydrogen peroxide after reacting with 0.5mM Ce(SO4)2 solution;

[0031] Figure 9 The Ta-B2S3 / CNT catalyst prepared for the example was tested under constant current density conditions (10 mA / cm²). -2 -90mA / cm -2 (The yield graph of hydrogen peroxide) Detailed Implementation

[0032] Specific Implementation Method 1: The preparation method of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst in this implementation method is carried out according to the following steps:

[0033] Step 1: Disperse pyromellitic acid, tantalum pentachloride and bismuth nitrate pentahydrate in methanol and sonicate them. Then transfer them to a high-pressure reactor and carry out a solvothermal reaction at a temperature of 110℃~140℃. After the reaction is completed, collect the solid phase and obtain tantalum-doped bismuth organometallic framework material (Ta / CAU-17) powder after washing and drying.

[0034] Step 2: Grind and mix tantalum-doped bismuth organometallic framework powder and dibenzyl disulfide to obtain a mixture;

[0035] Step 3: Under an argon atmosphere, the mixture is heated to 750~950℃ and carbonized to obtain a carbon nanotube-supported tantalum single-atom doped bismuth sulfide catalyst (Ta-B2S3 / CNT).

[0036] The carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst prepared in this embodiment uses metallic Bi and Ta as the core active centers, selects pyromellitic acid as the structure inducer, and dibenzyl disulfide as the sulfur source. Through precise control of the pyrolysis process in an argon inert atmosphere, a composite material with a unique hollow rod-like structure was successfully constructed.

[0037] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the molar ratio of tantalum pentachloride and bismuth nitrate pentahydrate in step one is (1~3):30.

[0038] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 1 or 2 in that the mass ratio of dibenzyl disulfide, tantalum pentachloride and bismuth nitrate pentahydrate in step 1 is controlled to be (350~450): (2~6): 75.

[0039] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the ultrasonic treatment in step one lasts for 20 to 50 minutes.

[0040] Specific Implementation Method 5: This implementation method differs from Specific Implementation Methods 1 to 4 in that the solvothermal reaction in step 1 is carried out at a temperature of 110℃~140℃ for 20~26 hours.

[0041] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the temperature is increased to 750-950℃ at a rate of 2-5℃ / min in step three.

[0042] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the heat preservation and carbonization treatment time in step three is 1 to 3 hours.

[0043] Specific Implementation Method Eight: In this implementation method, the application of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst involves using the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst in a two-electron oxygen reduction reaction (2e) via an RRDE device. - The performance of the catalyst was verified by testing hydrogen peroxide generation in the ORR (Organic Response Rate) test.

[0044] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Eight in that the tantalum single-atom doped bismuth sulfide catalyst supported on carbon nanotubes is prepared into a slurry, and the slurry is uniformly coated on a gas diffusion electrode (GDE) to prepare a working cathode; the working cathode is placed in an H-type electrochemical reactor equipped with KOH electrolyte, and oxygen is introduced to carry out a two-electron oxygen reduction reaction, thereby preparing hydrogen peroxide.

[0045] This embodiment drives oxygen to undergo a two-electron oxygen reduction reaction on the cathode surface by applying a potential of 0.1 to 0.7 V (relative to the reversible hydrogen electrode, vs. RHE) or operating at a constant current density of 10 to 90 mA / cm², thereby efficiently and continuously generating hydrogen peroxide.

[0046] This embodiment utilizes the precise control of the oxygen reduction pathway by the active sites of bismuth-tantalum sulfide on carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst, promoting the reaction preferentially along the 2e- electron beam. - The process proceeds along a specific pathway, resulting in the efficient and selective generation of H2O2. Furthermore, the carbon nanotube support not only enhances electron transport efficiency but also improves the catalyst's structural stability and lifespan under reaction conditions. This catalyst is suitable for various electrolysis environments, exhibits good process compatibility and reusability, and provides a feasible material solution for the efficient and green electrosynthesis of hydrogen peroxide, demonstrating broad prospects for industrial applications.

[0047] Example: The preparation method of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst in this example is carried out according to the following steps:

[0048] Step 1: Disperse 375 mg of pyromellitic acid, 2 mg of tantalum pentachloride and 75 mg of bismuth nitrate pentahydrate in methanol and sonicate for 30 min. Then transfer to a high-pressure reactor and carry out a solvothermal reaction at 120 °C for 24 h. After the reaction is completed, collect the solid phase, wash it with methanol several times, centrifuge and dry it to obtain a light yellow tantalum-doped bismuth metal-organic framework material (Ta / CAU-17) powder.

[0049] Step 2: Grind and mix all the tantalum-doped bismuth metal-organic framework material powder (Ta / CAU-17) prepared in Step 1 with 450 mg of dibenzyl disulfide to obtain a mixture;

[0050] Step 3: Under an argon atmosphere, the mixture is heated to 950℃ and held at a heating rate of 5℃ / min for 2 hours to obtain a carbonization treatment of tantalum single-atom doped bismuth sulfide catalyst supported on carbon nanotubes (Ta-B2S3 / CNT).

[0051] Comparative Example 1: The difference between this example and Example 1 is that 375 mg of pyromellitic acid and 75 mg of bismuth nitrate pentahydrate are dispersed in methanol and ultrasonically treated, while the other steps are the same.

[0052] The product obtained in this embodiment is denoted as Bi-SC.

[0053] Comparative Example 2: This example differs from Example 1 in that 375 mg of pyromellitic acid and 2 mg of tantalum pentachloride are dispersed in methanol and ultrasonically treated; the other steps are the same.

[0054] The product obtained in this embodiment is denoted as Ta-SC.

[0055] This embodiment employs a bimetallic (Bi-Ta) structure to construct a synergistic catalytic system. The catalyst has the following characteristics:

[0056] (i) A synergistic catalytic system is constructed using a bimetallic (Bi-Ta) structure, wherein:

[0057] (1) When tantalum is doped into the bismuth sulfide lattice, it disrupts the original electronic balance, causing lattice distortion and generating a large number of coordinatingly unsaturated bismuth active sites. These active sites can enhance the adsorption capacity for oxygen molecules. At the same time, tantalum can regulate the electronic structure of bismuth sulfide, optimize its adsorption of O2, and promote the adsorption of oxygen molecules. Intermediate formation;

[0058] (2) The carbon layer has high conductivity and large specific surface area. On the one hand, it can build a fast electron transport channel, accelerate the electron transfer between bismuth sulfide and the electrode, solve the problem of weak electron conduction of bismuth-based materials, and ensure the efficient transfer of electrons in the oxygen reduction reaction. On the other hand, the metal particles loaded on the carbon layer can avoid agglomeration and corrosion in the reaction. At the same time, the carbon defect sites can also help adsorb oxygen, and synergistically improve the catalytic efficiency.

[0059] (3) The Ta / CUA-17 precursor formed by hydrothermal reaction presents a solid cylindrical stacked morphology. After carbonization, it inherits the rod-shaped morphology while forming a hollow structure. This structure not only increases the specific surface area but also prevents the metal from becoming unstable during the electroreduction process.

[0060] (ii) Performance optimization path:

[0061] ① The metal distribution structure is controlled by adjusting the hydrothermal temperature (110-140℃), hydrothermal time (20~26h), sulfur source content (350mg-450mg of dibenzyl disulfide), carbonization temperature (750-950℃), heating rate (2℃ / min -5℃ / min), and atmosphere type (Ar).

[0062] ②Change the Ta / Bi molar ratio to (1-3):30 to regulate electron transfer efficiency;

[0063] ③ Inheriting the morphology of the precursor regulates electrical conductivity and mass transfer efficiency.

[0064] This embodiment overcomes the traditional catalyst dilemma of "activity-stability-selectivity" through a synergistic design of "metal electronic structure regulation-interface proton transport enhancement-three-dimensional conductive network construction". Example 1 shows the process parameters determined after performance optimization. The technical parameters of the products are compared in the table below:

[0065]

[0066] The morphological and structural characteristics and applications of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst prepared in the examples are as follows:

[0067] (1) Appearance

[0068] The catalyst morphology was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For example... Figure 1 As shown, the Ta / CUA-17 precursor prepared by hydrothermal reaction exhibits a cylindrical solid stacked morphology. Simultaneously, after high-temperature carbonization in an argon atmosphere, the metal precursor forms a hollow rod-like morphology. Furthermore, during the high-temperature carbonization process, some of the bismuth metal volatilizes, causing some of the hollow rod-like structures to shrink and collapse. Figure 2Metal agglomeration easily occurs during high-temperature carbonization, leading to uneven distribution of metal active sites. Energy-dispersive X-ray spectroscopy (EDX) is used to observe the elemental distribution of the Ta-Bi2S3 / CNT catalyst. Elemental composition analysis using EDX reveals that, except for the Cu substrate, C, S, Bi, and Ta can be detected. Figure 3 It can be seen that Bi, Ta, and S are loaded in carbon nanotubes, and the elements C, S, Bi, and Ta are uniformly distributed.

[0069] (2) Structure

[0070] X-ray photoelectron spectroscopy (XPS) has been used to study changes in the chemical environment and near-surface composition of Ta and Bi surfaces. For example... Figure 4 As shown, the spectrum of Ta-Bi2S3 / CNT contains several peaks corresponding to Bi and Ta, as well as five elements present in the sample: Bi, Ta, S, O and C.

[0071] (3) Construction and electrochemical testing of the electrocatalytic system:

[0072] Working electrode: Catalyst slurry (5 mg carbon nanotube-supported bismuth-tantalum sulfide catalyst + 20 µL Nafion + 780 µL ethanol + 200 µL H2O) is coated on the ring disk electrode or the gas diffusion layer.

[0073] Electrolyte: 0.1 M KOH solution (pH=13).

[0074] Operating parameters: room temperature, oxygen flow rate 30 sccm, applied potential 0-0.7 V vs. RHE or constant current density (10 mA / cm²). 2 -90 mA / cm 2 ).

[0075] The catalytic test results are as follows:

[0076] Test 1

[0077] 5 μL of catalyst slurry was uniformly coated onto the glassy carbon electrode surface of the annular disk apparatus, serving as the working electrode; Hg / HgO was selected as the reference electrode, and a carbon rod as the counter electrode. Before conducting electrochemical tests, 50 mL of 0.1 mol / L KOH electrolyte was injected into the single-port cell, and O2 gas was continuously introduced for 30 minutes to ensure that the electrolyte reached O2 saturation. During the electrocatalytic O2 reduction process, O2 gas was continuously introduced at a flow rate of 30 mL / min, and the selectivity of the target product was detected by the electrochemical testing system. Specific test results are as follows: Figure 5-7 As shown.

[0078] Figure 5-6This study details the Lsv and selectivity performance of three catalysts—Ta-Bi₂S₃ / CNT, Ta-SC, and Bi-SC—at different voltages (vs. RHE). Data shows that at the same voltage, the Ta-Bi₂S₃ / CNT catalyst exhibits a higher ring current, indicating that it primarily undergoes a two-electron reduction reaction. A reduction peak is observed in the disk current, possibly due to rapid oxygen consumption and insufficient supply. Within the voltage range of 0 to 0.65 V, the selectivity of Ta-Bi₂S₃ / CNT for H₂O₂ products consistently remains above 90%. When the voltage is in the range of 0.25–0.45 V, its H₂O₂ selectivity approaches 100%. In stark contrast, under the same testing conditions, the H₂O₂ selectivity of the Bi-SC catalyst is below 60%, and that of the Ta-SC catalyst is less than 82%.

[0079] Further analysis revealed that at 1 mA / cm -2 At a current density of [value missing], the onset potential of Ta-Bi₂S₃ / CNT is 0.66 V (vs. RHE), significantly higher than that of Bi-SC (0.62 V vs. RHE) and Ta-SC (0.54 V vs. RHE). Figure 7 This fully confirms its role in the two-electron oxygen reduction reaction (2e). - Excellent intrinsic activity in ORR.

[0080]

[0081] Test 2

[0082] 10 μL of catalyst slurry was uniformly coated onto the surface of the gas diffusion layer to serve as the working electrode; Hg / HgO was selected as the reference electrode, and a carbon rod was used as the counter electrode. Before conducting electrochemical tests, 50 mL of 0.1 mol / L KOH electrolyte was injected into both the cathode and anode chambers, and O2 gas was continuously introduced into the cathode chamber for 30 minutes to ensure that the cathode electrolyte reached O2 saturation.

[0083] Test results are as follows Figure 8-9 As shown: Ta-B2S3 / CNT catalyst at 10-90 mA cm⁻¹ -2 Within the specified current density range, the H2O2 yield exhibits an approximately linear increasing trend. When the current density reaches a specific value, the H2O2 yield can reach a maximum of 8.76 molg. at -1 h -1 It exhibits excellent catalytic performance.

[0084] This invention not only discloses a method for preparing a carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst, but also further reveals the specific application scenarios of this catalyst. The catalyst prepared by the method of this invention is mainly suitable for the electrochemical oxygen reduction to prepare hydrogen peroxide. The relevant reaction conditions have been described in detail above and will not be repeated here.

[0085] This preparation method has significant advantages: the technical route is simple and the operation process is easy to implement. The first product is obtained by hydrothermal precipitation of bismuth salt, tantalum salt, and the structure-directing agent trimesoate. Then, dibenzyl disulfide is added to provide a sulfur source. Subsequently, the product is subjected to high-temperature sulfidation and carbonization treatment to achieve mass synthesis of the catalyst. When using this catalyst for catalytic reactions, the reaction conditions are mild, and hydrogen peroxide can be generated with high selectivity at relatively low voltage.

[0086] From a performance perspective, the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst prepared by this method exhibits superior characteristics. Firstly, it demonstrates exceptional stability and excellent mechanical strength, maintaining stable catalytic performance even during prolonged electrochemical oxygen reduction reactions, effectively preventing catalyst loss and thus improving product quality and reducing production costs. Secondly, this catalyst offers advantages such as low cost, environmental friendliness, and extremely high selectivity for hydrogen peroxide products. In the electrocatalytic oxygen reduction reaction, the yield of hydrogen peroxide products generated using this catalyst reached as high as 8.76 mol / g. -1 h -1 With a selectivity approaching 100%, it significantly reduces the generation of byproduct water and greatly improves energy utilization efficiency.

[0087] In summary, the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst prepared by this invention successfully overcomes the problems of poor stability, low hydrogen peroxide yield, high energy consumption, and environmental impact associated with traditional catalysts.

[0088] Obviously, the above description is only a portion of the preferred embodiments and core technical principles employed in this invention. Those skilled in the art should understand that this invention is not limited to the specific embodiments described above. Without departing from the core technical concept of this invention, those skilled in the art can make various modifications, adjustments, and substitutions, and all such changes should be included within the scope of protection of this invention. Therefore, although the invention has been described in detail through the above embodiments, the scope of protection of this invention is not limited thereto. Based on the innovative concept of this invention, more equivalent embodiments can be derived, and the actual scope of protection of this invention will be determined by the appended claims.

Claims

1. A tantalum single-atom-doped bismuth sulfide catalyst supported on carbon nanotubes, characterized in that... The tantalum single-atom-doped bismuth sulfide catalyst supported on carbon nanotubes is prepared by carbonizing tantalum-doped bismuth metal-organic framework material and dibenzyl disulfide at a temperature of 750~950℃ under an argon atmosphere; wherein the tantalum-doped bismuth metal-organic framework material is prepared by solvothermal reaction using pyromellitic acid, tantalum pentachloride and bismuth nitrate pentahydrate as raw materials.

2. A method for preparing a carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst, characterized in that... The preparation method of carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst is carried out according to the following steps: Step 1: Disperse pyromellitic acid, tantalum pentachloride and bismuth nitrate pentahydrate in methanol and sonicate them. Then transfer them to a high-pressure reactor and carry out a solvothermal reaction at a temperature of 110℃~140℃. After the reaction is completed, collect the solid phase, wash and dry it to obtain tantalum-doped bismuth metal-organic framework material powder. Step 2: Grind and mix tantalum-doped bismuth metal-organic framework powder and dibenzyl disulfide to obtain a mixture; Step 3: Under an argon atmosphere, the mixture is heated to 750~950℃ and carbonized to obtain a carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst.

3. The method for preparing the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 2, characterized in that... In step one, the molar ratio of tantalum pentachloride and bismuth nitrate pentahydrate is (1~3):

30.

4. The method for preparing the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 2, characterized in that... In step one, the mass ratio of pyromellitic acid, tantalum pentachloride and bismuth nitrate pentahydrate is controlled as (350~450):(2~6):

75.

5. The method for preparing the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 2, characterized in that... In step one, ultrasonic treatment lasts for 20-50 minutes.

6. The method for preparing the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 2, characterized in that... In step one, the solvothermal reaction is carried out at a temperature of 110℃~140℃ for 20~26 hours.

7. The method for preparing the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 2, characterized in that... In step three, the temperature is increased to 750-950℃ at a rate of 2-5℃ / min.

8. The method for preparing the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 2, characterized in that... The heat preservation and carbonization treatment in step three takes 1 to 3 hours.

9. The application of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst prepared according to claim 2, characterized in that... The method involves using a carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst to prepare hydrogen peroxide in a two-electron oxygen reduction reaction.

10. The application of the carbon nanotube-supported tantalum single-atom-doped bismuth sulfide catalyst according to claim 9, characterized in that... A slurry of tantalum single-atom-doped bismuth sulfide catalyst supported on carbon nanotubes was prepared and uniformly coated onto a rotating disk electrode or a gas diffusion electrode to prepare a working cathode. The working cathode was placed in an electrochemical reactor equipped with KOH electrolyte, and oxygen was introduced to carry out a two-electron oxygen reduction reaction to prepare hydrogen peroxide.

Images