Three-dimensional porous sulfur-doped tin-antimony-nickel electrode and preparation method and application thereof

Abstract

The invention discloses a three-dimensional porous sulfur-doped tin-antimony-nickel electrode and a preparation method and application thereof.The specific operation process includes the steps that a carrier is pretreated, the titanium carrier is used as a substrate, a sulfur-containing surfactant and tin-antimony-nickel metal salt are used as precursors, absolute ethyl alcohol and hydrochloric acid are used as solvents, and the three-dimensional porous sulfur-doped tin-antimony-nickel electrode is obtained; loading a sulfur-containing nanoparticle precursor material on the surface of the titanium carrier through a hydrothermal method; and drying the hydrothermal precursor material, and roasting in a muffle furnace to finally obtain the three-dimensional porous sulfur-doped tin-antimony-nickel-titanium substrate electrode. The catalyst disclosed by the invention has a three-dimensional porous spherical structure, the active specific surface area is obviously increased, the path of diffusing reactants to active sites is effectively shortened, the mass transfer resistance is reduced, the transfer of electrons and protons is promoted, and the reaction performance is improved. Sulfur doping not only improves the electrochemical reaction rate, conductivity and stability, but also shows high activity and high Faraday efficiency in electrocatalytic ozone production and chlorine evolution reactions.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrocatalysis, and in particular relates to a three-dimensional porous sulfur-doped tin-antimony-nickel electrode and a preparation method and application thereof. Background Art

[0002] Ozone (O3) and sodium hypochlorite (NaClO), as important products of electrocatalytic anode reactions, are of great value in the fields of water purification and wastewater treatment due to their strong oxidizing ability. Ozone can not only directly oxidize organic pollutants, but also generate hydroxyl radicals (·OH) and other reactive oxygen species by decomposition in water, thereby achieving deep oxidation of difficult-to-degrade pollutants. In addition, ozone has a short half-life, and its oxidation process does not produce persistent residues, which meets green environmental protection requirements. Sodium hypochlorite, as a liquid oxidant, has good disinfection and sterilization effects, can effectively reduce pathogenic microorganisms in wastewater, and is suitable for large-scale wastewater treatment. Therefore, the synergistic effect of ozone and sodium hypochlorite provides an efficient, economical and environmentally friendly solution for wastewater treatment.

[0003] At present, nickel-doped antimony tin oxide (Ni-ATO) is the most common anode catalyst in electrochemical ozone production (EOP) and chlorine evolution reaction (CER). Ni-ATO has good electrochemical stability and catalytic activity, and is therefore widely used in the field of electrocatalytic oxidation. However, the existing preparation methods of Ni-ATO still have many limitations, which affect its catalytic performance and industrial application value. The main preparation methods of Ni-ATO are sol-gel method and electrodeposition method. Although the sol-gel method is more common, its preparation process is cumbersome and requires multiple heating and cooling cycles. Not only is the process complicated, but the electrode surface is prone to "cracks", resulting in poor electrode density, affecting its performance and durability. Although the electrodeposition method can reduce the "cracking" phenomenon, its preparation cost is high, and the microstructure of the metal oxide active layer is relatively loose, which affects the service life of the electrode. In addition, the Ni-ATO catalysts prepared by the above methods usually exhibit a two-dimensional (2D) flat structure. This structure leads to insufficient exposure of active sites and a low distribution density. The limited effective specific surface area hinders mass transfer at the three-phase interface, which is not conducive to the sufficient adsorption and efficient conversion of reactants. The above structural defects collectively make it difficult to fully exert the intrinsic activity of the catalyst, ultimately restricting the improvement of the overall catalytic performance. Therefore, how to simplify the catalyst preparation process and increase the number and distribution of active sites on the electrode surface, thereby improving its catalytic activity and long-term stability in the EOP and CER processes, has become an important research direction. Summary of the Invention

[0004] The present invention aims to address the problems of the prior art by providing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode, its preparation method, and its application. This invention incorporates a sulfur-containing surfactant into a titanium-based metal oxide electrode and supports the sulfur-doped tin-antimony-nickel on a titanium substrate through a hydrothermal sulfurization treatment, reducing costs while improving the catalyst's stability and reactivity. When used in EOP and CER reactions, this electrode generates large amounts of active oxygen and available chlorine for wastewater treatment and disinfection.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In one aspect, the method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode comprises the following steps:

[0007] (1) Pretreatment of titanium support: The cut titanium support (titanium felt (TiF), titanium plate (TiP) or titanium foam (TF)) is sequentially rinsed with deionized water, alkali washed, acid washed, and ultrasonically washed;

[0008] (2) Preparation of sulfur precursor solution: Add a tin-containing compound (tin source), a nickel-containing compound (nickel source), an antimony-containing compound (antimony source) and a sulfur-containing surfactant to a mixed solvent of ethanol and hydrochloric acid in sequence, and ultrasonically treat for 10-30 minutes to mix them evenly to obtain a sulfur precursor solution A. The purpose of adding hydrochloric acid in this step is to prevent Sb from hydrolyzing.

[0009] (3) Hydrothermal sulfurization treatment: The titanium support pretreated in step (1) is placed in the sulfur precursor solution A obtained in step (2), and placed in a hydrothermal kettle for hydrothermal reaction. After the reaction is completed, it is cooled to room temperature, the hydrothermal titanium substrate is taken out, repeatedly washed with distilled water and ethanol, and vacuum dried to obtain the precursor material.

[0010] (4) Calcination treatment: The precursor material in step 3) is placed in a muffle furnace and calcined to obtain the three-dimensional porous sulfur-doped tin antimony nickel electrode.

[0011] Furthermore, the step (1) is specifically as follows: cutting the titanium carrier into a certain size and rinsing it with deionized water to remove surface impurities, completely immersing the cut and rinsed titanium carrier in a NaOH solution, and then placing it in an oil bath for heating for 30-60 minutes. After taking it out, rinsing the titanium carrier with deionized water, then placing the washed titanium carrier in an oxalic acid solution, and treating it in an oil bath for 30-60 minutes. After the treatment is completed, ultrasonically rinsing the titanium carrier with deionized water to remove excess oxalic acid solution on the surface, and repeating the ultrasonic rinsing step 2-4 times until no obvious brown liquid seeps out of the cleaning solution. Finally, the treated titanium carrier is placed in anhydrous ethanol for storage. The purpose of the acid pickling in this step is to roughen the surface of the titanium carrier, which helps to enhance the bonding strength of subsequent deposits with the titanium substrate, prevent the coating from falling off, improve the conductivity of the electrode, extend the service life, and remove surface oxides and impurities.

[0012] Furthermore, in step (1), the mass fraction of the NaOH solution is 15-30%, the mass fraction of the oxalic acid solution is 15-20%, and the temperature of the oil bath is 60-90°C.

[0013] Furthermore, in step (2), the tin-containing compound is one of tin tetrachloride pentahydrate, stannous nitrate, and stannous oxalate; the antimony-containing compound is one of antimony trioxide, antimony trichloride, and antimony pentoxide; the nickel-containing compound is one of nickel dichloride hexahydrate, nickel sulfide, nickel nitrate, and nickelous oxide; and the sulfur-containing surfactant is one of disodium lauryl polyoxyethylene ether sulfosuccinate (DLS), ammonium dodecylbenzenesulfonate (CaDBs), sodium p-toluenesulfonate (PTSS), hexadecyltrimethylammonium p-toluenesulfonate (CTAT), and sodium p-toluenesulfinate (PTSA).

[0014] Furthermore, in step (2), the molar ratio of the added tin-containing compound, nickel-containing compound, and antimony-containing compound is (10-100):(1-20):(1-20), and the volume ratio of hydrochloric acid to anhydrous ethanol is 1:4-30.

[0015] Furthermore, in step (2), the concentration of the tin compound in the sulfur precursor solution A is 100 g / L-300 g / L, the concentration of the antimony compound is 1 g / L-10 g / L, the concentration of the nickel compound is 1 g / L-5 g / L, and the concentration of the sulfur-containing surfactant is 0.2 g / L-5 g / L.

[0016] Furthermore, in step (3), the hydrothermal temperature is 120-180° C., the time is 5-12 h, and the vacuum drying temperature is 50-70° C., the time is 20-24 h.

[0017] Furthermore, in step (4), the calcination temperature in the muffle furnace is 400-600°C, the calcination time is 1-3h, and the heating rate is 2-10°C / min.

[0018] The present invention also proposes a three-dimensional porous sulfur-doped tin-antimony-nickel electrode prepared by the method described above.

[0019] The three-dimensional porous sulfur-doped tin-antimony-nickel electrode was used for the electrolysis of water to produce ozone. The current was controlled by a constant current meter. A single electrolytic cell was used for the reaction. A 0.5 M H2SO4 solution was used as the electrolyte. The sulfur-doped tin-antimony-nickel electrode was used as the working electrode and a platinum sheet was used as the counter electrode. The reaction current density was controlled at 150-300 mA cm -2 , electrolyze water to produce ozone.

[0020] The three-dimensional porous sulfur-doped tin-antimony-nickel electrode was used in the electrocatalytic chlorine evolution reaction. The current was controlled by a constant current meter. The reaction was carried out in an H-type electrolytic cell. A 1M NaCl solution (adjusted to pH = 2 with H2SO4) was used as the electrolyte. The sulfur-doped tin-antimony-nickel electrode was used as the working electrode and a platinum sheet was used as the counter electrode. The reaction current density was controlled at 50-300 mA cm -2 , and chlorine evolution reaction is carried out.

[0021] To address the short lifespan and poor activity of conventional Ni-Sb-SnO2 / Ti electrodes, the present invention introduces sulfur-containing surfactants (disodium lauryl polyoxyethylene ether sulfosuccinate, ammonium dodecylbenzenesulfonate, sodium p-toluenesulfonate, hexadecyltrimethylammonium p-toluenesulfonate, and sodium p-toluenesulfinate) into the Ni-Sb-SnO2 / Ti electrode. Sulfur doping effectively enhances the bonding between the coating and the substrate, modulating the adsorption energy of reactant intermediates and enabling the continuous production of high concentrations of ozone and sodium hypochlorite during the electrolysis process.

[0022] By adopting the above technology, compared with the existing ozone-generating and sodium hypochlorite electrodes, the present invention has the following beneficial effects:

[0023] (1) The sulfur doping of the present invention replaces the precious metal raw materials in traditional technology. Tin, antimony, nickel metal salts and a small amount of sulfur-containing surfactant are ultrasonically mixed with a solvent to form a precursor solution. Then, the electrode sheet can be prepared by a one-step hydrothermal sulfurization-roasting process. The preparation process is simple and the production cost is greatly reduced.

[0024] (2) By comparison, the sulfur-doped tin-antimony-nickel electrode prepared by the present invention is superior to the traditional DSA (Dimensionally Stable Anode) electrode in the electrocatalytic production of ozone at industrial current density. After long-term power-on operation, the catalytic activity does not decrease significantly, indicating that sulfur doping is an effective strategy to improve electrocatalytic stability.

[0025] (3) Under the same test conditions, compared with the Faraday efficiency of the DSA (Dimensionally Stable Anode) electrode in the electrocatalytic production of ozone and sodium hypochlorite reported in the literature, the DLS-NATO / TiF electrode prepared in the present invention has better catalytic performance. The experimental results show that the electrode achieved a gaseous ozone yield of 24.2% and an effective chlorine concentration of 95% in the electrocatalytic ozone production (EOP) and chlorine evolution (CER) reactions, respectively, which are significantly higher than those of the traditional DSA electrode. This shows that sulfur doping can effectively regulate the electronic structure of the tin-antimony-nickel electrode, showing higher catalytic activity and excellent performance in the electrocatalytic production of ozone and sodium hypochlorite, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a scanning electron microscope image of the DLS-NATO / TiF electrode obtained in Example 1 at 30 μm;

[0027] Figure 2 This is a scanning electron microscope image of the DLS-NATO / TiF electrode obtained in Example 1 at 20 μm;

[0028] Figure 3 This is a scanning electron microscope image of the DLS-NATO / TiF electrode obtained in Example 1 at 10 μm;

[0029] Figure 4 This is a transmission electron microscope observation image of the DLS-NATO / TiF electrode obtained in Example 1 at 20 nm;

[0030] Figure 5 This is a transmission electron microscope observation image of the DLS-NATO / TiF electrode obtained in Example 1 at 10 nm;

[0031] Figure 6 This is a transmission electron microscope observation image of the DLS-NATO / TiF electrode obtained in Example 1 at 5 nm;

[0032] Figure 7 Comparison of real-time data of gaseous ozone concentration when the electrodes obtained in Examples 1-5 and Comparative Example 1 are used for electrocatalytic ozone production;

[0033] Figure 8 Comparison of the Faradaic efficiency of the electrodes obtained in Examples 1-5 and Comparative Example 1 when used for electrocatalytic production of ozone;

[0034] Figure 9The DLS-NATO / TiF electrodes obtained in Example 1 and Comparative Example 1 were subjected to a current density of 500 mA·cm in a 0.5 M H2SO4 solution. -2 Accelerated life test diagram of EOP under conditions;

[0035] Figure 10 This is a graph showing the change in ozone concentration over time when the NATO / TiF electrode obtained in Comparative Example 1 is used for electrocatalytic ozone production;

[0036] Figure 11 Comparison of data on effective chlorine concentration when the electrodes obtained in Examples 1-5 and Comparative Example 1 are used for electrocatalytic preparation of sodium hypochlorite;

[0037] Figure 12 Comparison of Faradaic efficiency data when the electrodes obtained in Examples 1-5 and Comparative Example 1 are used for electrocatalytic preparation of sodium hypochlorite;

[0038] Figure 13 The DLS-NATO / TiF electrode obtained in Example 1 and Comparative Example 1 was subjected to a current density of 250 mA·cm in a 1 M NaCl (pH = 2) solution. -2 Accelerated life test diagram of CER under conditions;

[0039] Figure 14 A comparison chart of the Faraday efficiency of electrodes obtained with different sulfur contents when used for electrocatalytic ozone production;

[0040] Figure 15 This is a comparison chart of the Faraday efficiency of electrodes obtained with different sulfur contents when used for electrocatalytic preparation of sodium hypochlorite. DETAILED DESCRIPTION

[0041] The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0042] Example 1: Preparation of a DLS-NATO / TiF electrode, comprising the following steps:

[0043] (1) Pretreatment of titanium carrier: Cut the titanium felt into 2×2 cm and rinse it with deionized water to remove surface impurities. The cut and rinsed titanium carrier is completely immersed in 20% NaOH solution and placed in a 75°C oil bath for heating treatment for 40 minutes. During this period, it is turned over every 20 minutes to ensure uniform treatment. After the treatment is completed, the titanium carrier is taken out and thoroughly rinsed with deionized water. Subsequently, the cleaned titanium carrier is transferred to a 15% oxalic acid solution and treated in an 80°C oil bath for 40 minutes. It is turned over every 20 minutes. After the treatment is completed, the titanium carrier is ultrasonically rinsed with deionized water to remove the residual oxalic acid solution on the surface. The ultrasonic rinsing step is repeated twice until there is no obvious brown liquid seeping out of the cleaning solution.

[0044] (2) Preparation of sulfur precursor solution: 4.2 g SnCl4·5H2O, 250 mg SbCl3, 271.9 mg NiCl2·6H2O, and 100 mg DLS were added sequentially to a mixed solution of 27 mL anhydrous ethanol and 3 mL concentrated hydrochloric acid. The mixed solution was ultrasonicated in an ultrasonicator for 30 min until all components were fully dissolved and a uniform and transparent sulfur precursor solution was formed.

[0045] (3) Hydrothermal sulfurization treatment: The pretreated titanium support was placed in the sulfur precursor solution prepared in step (2) and placed in a hydrothermal reactor for reaction at 180°C for 12 hours. After the reaction, it was cooled to room temperature. The hydrothermally treated titanium substrate was removed and repeatedly washed with distilled water and anhydrous ethanol. The resulting product was placed in a vacuum drying oven and dried at 70°C for 24 hours. After drying, the sample was placed in a muffle furnace, heated to 500°C, and then calcined for 2 hours at a heating rate of 2°C / min.

[0046] The scanning electron microscope (SEM) images of the microstructure of the DLS-NATO / TiF electrode prepared in Example 1 at 30 μm, 20 μm and 10 μm magnifications are as follows: Figure 1-3 Transmission electron microscopy (TEM) images at 20 nm, 10 nm, and 5 nm magnifications are shown in FIG. Figure 4-6 As shown. Figure 3 As shown in the figure, the prepared DLS-NATO / TiF electrode has a three-dimensional porous structure. This special structure can enhance the active specific surface area, and the pore structure provides a reaction microenvironment for the EOP and CER active sites. Figure 4-6 The crystallinity of SnO2 was demonstrated, indicating that it has good crystallinity.

[0047] The DLS-NATO / TiF electrode of Example 1 is used for electrolysis of water to produce ozone:

[0048] The voltage and current were controlled by a constant current meter. A single cell was used for the reaction. The DLS-NATO / TiF electrode prepared in Example 1 was used as the working electrode, a platinum sheet was used as the counter electrode, and the electrolyte was a 0.5M H2SO4 solution. The ozone gas generated by electrolysis in the electrolytic cell was connected to an ozone detector through the gas outlet, enabling real-time detection of the ozone gas concentration. During the electrocatalytic ozone production reaction, the current density was controlled at 250 mA cm -2 , the cell voltage is controlled between 3-6V, and the reaction time is 60min. The real-time monitoring diagram of the gaseous ozone concentration generated by the DLS-NATO / TiF electrode is shown in Figure 2. Figure 7As shown in the experimental results, the ozone concentration in the initial stage showed a rapid growth trend, reaching a maximum of 502ppm. After 50min of reaction, the gaseous ozone concentration can be stabilized at 481ppm. The Faraday efficiency of the gaseous ozone concentration generated by the DLS-NATO / TiF electrode is shown in Figure 8 As shown, its Faradaic efficiency reaches 24.2%.

[0049] In order to verify the EOP stability of the prepared electrode, an accelerated life test was conducted using the DLS-NATO / TiF electrode of Example 1 as the anode and the platinum electrode as the cathode. The experimental conditions were as follows: the current density was set to 500 mA·cm -2 , the electrolyte is 0.5MH2SO4 solution, when the voltage exceeds 10V, it is considered that the electrode has reached the life limit. Figure 9 As shown, the voltage of the DLS-NATO / TiF electrode prepared in Example 1 did not change significantly within 900 h, indicating that it has good stability.

[0050] The DLS-NATO / TiF electrode of Example 1 is used for chlorine evolution reaction:

[0051] The voltage and current were controlled by a constant current meter, and the reaction was carried out in an H-type electrolytic cell. A DLS-NATO / TiF electrode was used as the working electrode, a platinum sheet was used as the counter electrode, and the electrolyte was a 1M NaCl solution (pH = 2). During the electrochemical chlorine evolution reaction, the current density was controlled at 250 mA cm -2 , the cell voltage was controlled between 3-6V, and the reaction time was 90s. After the reaction, 5mL of electrolyte was taken and 20mL of 2% KI solution and 1mL of standard starch solution were added thereto as indicators. At this time, the solution color turned blue. Then, 4mM Na2S2O3 solution was added dropwise until the color completely disappeared. The volume of Na2S2O3 consumed was recorded to calculate the effective chlorine concentration and Faraday efficiency. The effective chlorine concentration and Faraday efficiency generated by the DLS-NATO / TiF electrode are shown as follows: Figure 11 and Figure 12 As shown, the effective chlorine concentration can reach 63ppm and the Faraday efficiency is 95%.

[0052] In order to verify the stability of the chlorine evolution reaction of the prepared electrode, an accelerated life test was carried out with the DLS-NATO / TiF electrode as the anode and the platinum electrode as the cathode. The experimental conditions were as follows: the current density was set at 250 mA cm -2 , the electrolyte is 1M NaCl (pH=2) solution, when the voltage exceeds 10V, it is considered that the electrode has reached the life limit. Figure 13 As shown in Figure 3, the prepared DLS-NATO / TiF electrode can operate stably for 400 h, indicating that it has good stability.

[0053] Example 2: Preparation of a PTSA-NATO / TF electrode, comprising the following steps:

[0054] (1) Pretreatment of titanium carrier: Cut the titanium foam into 2×2 cm and rinse with deionized water to remove surface impurities. The cut and rinsed titanium carrier is completely immersed in 15% NaOH solution and placed in an 85°C oil bath for heating treatment for 60 minutes. During this period, it is turned over every 20 minutes to ensure uniform treatment. After the treatment is completed, the titanium carrier is taken out and thoroughly rinsed with deionized water. Subsequently, the cleaned titanium carrier is transferred to a 20% oxalic acid solution and treated in an 80°C oil bath for 40 minutes, turning it over every 20 minutes. After the treatment is completed, the titanium carrier is ultrasonically rinsed with deionized water to remove the oxalic acid solution remaining on the surface. The ultrasonic rinsing step is repeated twice until there is no obvious brown liquid seeping out of the cleaning solution.

[0055] (2) Preparation of sulfur precursor solution: 4.5 g SnCl4·5H2O, 38 mg Sb2O3, 110 mg NiCl2·6H2O, and 20 mg PTSA were added to a mixed solution of 27 mL anhydrous ethanol and 4 mL concentrated hydrochloric acid in sequence. The mixed solution was placed in an ultrasonicator and sonicated for 30 min until all components were fully dissolved and a uniform and transparent sulfur precursor solution was formed.

[0056] (3) Hydrothermal sulfurization treatment: The pretreated titanium support was placed in the sulfur precursor solution prepared in step (2) and placed in a hydrothermal reactor for reaction at 180°C for 12 hours. After the reaction, it was cooled to room temperature. The hydrothermally treated titanium substrate was removed and repeatedly washed with distilled water and anhydrous ethanol. The resulting product was placed in a vacuum drying oven and dried at 70°C for 24 hours. After drying, the sample was placed in a muffle furnace, heated to 500°C, and then calcined for 2 hours at a heating rate of 5°C / min.

[0057] The PTSA-NATO / TF electrode of Example 2 is used for electrolysis of water to produce ozone:

[0058] During the preparation of the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 2 of the same size, and the remaining operating conditions were the same as the experimental process of preparing ozone by electrolysis of water in Example 1.

[0059] The PTSA-NATO / TiF electrode of Example 2 is used for chlorine evolution reaction:

[0060] During the process of preparing the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 2 of the same size, and the remaining operating conditions were the same as the chlorine evolution experimental process in Example 1.

[0061] Example 3: Preparation of a CaDBs-NATO / TiP electrode, comprising the following steps:

[0062] (1) Pretreatment of titanium carrier: Cut the titanium plate into 2.5×2.5 cm and rinse it with deionized water to remove surface impurities. The cut and rinsed titanium carrier is completely immersed in 15% NaOH solution and placed in an 80°C oil bath for heating treatment for 30 minutes. During this period, it is turned over every 15 minutes to ensure uniform treatment. After the treatment is completed, the titanium carrier is taken out and thoroughly rinsed with deionized water. Subsequently, the cleaned titanium carrier is transferred to a 15% oxalic acid solution and treated in a 75°C oil bath for 30 minutes. It is turned over every 15 minutes to ensure uniform treatment. After the treatment is completed, the titanium carrier is ultrasonically rinsed with deionized water to remove the residual oxalic acid solution on the surface. This process is repeated 4 times until no obvious brown liquid seeps out of the cleaning solution.

[0063] (2) Preparation of sulfur precursor solution: 3.5 g Sn(NO3)2, 50 mg Sb2O3, 130 mg Ni(NO3)2, and 30 mg CaDBs were added to a mixed solution of 30 mL anhydrous ethanol and 4.5 mL concentrated hydrochloric acid in sequence. The mixed solution was placed in an ultrasonicator and sonicated for 30 min until all components were fully dissolved and a uniform and transparent sulfur precursor solution was formed.

[0064] (3) Hydrothermal sulfurization treatment: The pretreated titanium support was placed in the sulfur precursor solution prepared in step (2) and placed in a hydrothermal reactor for reaction at 160°C for 12 hours. After the reaction, it was cooled to room temperature. The hydrothermally treated titanium substrate was removed and repeatedly washed with distilled water and anhydrous ethanol. The resulting product was placed in a vacuum drying oven and dried at 70°C for 24 hours. After drying, the sample was placed in a muffle furnace, heated to 550°C, and then calcined for 2 hours at a heating rate of 4°C / min.

[0065] The CaDBs-NATO / TiP electrode of Example 3 is used for electrolysis of water to produce ozone:

[0066] During the process of preparing the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 3 of the same size, and the remaining operating conditions were the same as the experimental process of preparing ozone by electrolysis of water in Example 1.

[0067] The CaDBs-NATO / TiP electrode of Example 3 is used for chlorine evolution reaction:

[0068] During the process of preparing the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 3 of the same size, and the remaining operating conditions were the same as the chlorine evolution experimental process in Example 1.

[0069] Example 4: Preparation of a CTAT-NATO / TiF electrode, comprising the following steps:

[0070] (1) Pretreatment of titanium carrier: Cut the titanium felt into 2×2 cm and rinse it with deionized water to remove surface impurities. Immerse the cut and rinsed titanium carrier completely in 25% NaOH solution and place it in an 80°C oil bath for heating for 60 minutes, turning it over every 30 minutes to ensure uniform treatment. After the treatment is completed, take out the titanium carrier and rinse it thoroughly with deionized water. Subsequently, transfer the cleaned titanium carrier to a 20% oxalic acid solution and treat it in an 80°C oil bath for 60 minutes, turning it over every 30 minutes. After the treatment is completed, ultrasonically rinse the titanium carrier with deionized water to remove the residual oxalic acid solution on the surface. Repeat this process twice until there is no obvious brown liquid seeping out of the cleaning solution.

[0071] (2) Preparation of sulfur precursor solution: 3.5 g SnC2O4, 55 mg Sb2O5, 120 mg NiO, and 50 mg CTAT were added to a mixed solution of 25 mL anhydrous ethanol and 4.5 mL concentrated hydrochloric acid in sequence. The mixed solution was placed in an ultrasonicator and sonicated for 30 min until all components were fully dissolved and a uniform and transparent sulfur precursor solution was formed.

[0072] (3) Hydrothermal sulfurization treatment: The pretreated titanium support was placed in the sulfur precursor solution prepared in step (2) and placed in a 160°C oven for reaction for 14 h. After the reaction, the support was cooled to room temperature. The hydrothermally treated titanium support was removed and repeatedly washed with distilled water and anhydrous ethanol. The resulting product was placed in a vacuum drying oven and dried at 70°C for 20 h. After drying, the sample was placed in a muffle furnace and calcined at 600°C for 1 h, with a heating rate set at 5°C / min.

[0073] The CTAT-NATO / TiF electrode of Example 4 is used for electrolysis of water to produce ozone:

[0074] During the process of preparing the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 4 of the same size, and the remaining operating conditions were the same as the experimental process of preparing ozone by electrolysis of water in Example 1.

[0075] The CTAT-NATO / TiF electrode of Example 4 is used for chlorine evolution reaction:

[0076] During the preparation of the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 4 of the same size, and the remaining operating conditions were the same as the chlorine evolution experimental process in Example 1.

[0077] Example 5: Preparation of a PTSS-NATO / TiP electrode, comprising the following steps:

[0078] (1) Pretreatment of titanium carrier: Cut the titanium plate into 2×2 cm and rinse it with deionized water to remove surface impurities. The cut and rinsed titanium carrier is completely immersed in 25% NaOH solution and placed in a 90°C oil bath for heating treatment for 50 minutes. During this period, it is turned over every 25 minutes to ensure uniform treatment. After the treatment is completed, the titanium carrier is taken out and thoroughly rinsed with deionized water. Subsequently, the cleaned titanium carrier is transferred to a 20% oxalic acid solution and treated in an 80°C oil bath for 50 minutes. It is turned over every 25 minutes to ensure uniform treatment. After the treatment is completed, the titanium carrier is ultrasonically rinsed with deionized water to remove the residual oxalic acid solution on the surface. This process is repeated 3 times until there is no obvious brown liquid seeping out of the cleaning solution.

[0079] (2) Preparation of precursor solution: 3.5 g SnC2O4, 75 mg SbCl3, 83 mg NiCl2·6H2O, and 50 mg PTSS were added to a mixed solution of 20 mL anhydrous ethanol and 2 mL concentrated hydrochloric acid in sequence. The mixed solution was placed in an ultrasonicator and sonicated for 30 min until all components were fully dissolved and a uniform and transparent precursor solution was formed.

[0080] (3) Hydrothermal sulfurization treatment: The pretreated titanium support was placed in the precursor solution prepared in step (2) and placed in a 140°C oven for 6 h. After the reaction, the titanium support was cooled to room temperature. The hydrothermally treated titanium substrate was removed and repeatedly washed with distilled water and anhydrous ethanol. The resulting product was placed in a vacuum drying oven and dried at 70°C for 24 h. After drying, the sample was placed in a muffle furnace and calcined at 550°C for 1 h, with a heating rate set at 3°C / min.

[0081] The PTSS-NATO / TiP electrode of Example 5 is used for electrolysis of water to produce ozone:

[0082] During the preparation of the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 5 of the same size, and the remaining operating conditions were the same as the experimental process of preparing ozone by electrolysis of water in Example 1.

[0083] The PTSS-NATO / TiP electrode of Example 5 is used for chlorine evolution reaction:

[0084] During the process of preparing the electrode anode using the electrode prepared in Example 1, the added electrode in Example 1 was replaced with an electrode prepared in Example 5 of the same size, and the remaining operating conditions were the same as the chlorine evolution experimental process in Example 1.

[0085] Comparative Example 1: Preparation of a NATO / TiF electrode, comprising the following steps:

[0086] (1) Pretreatment of titanium carrier: Cut the titanium felt into 2×2 cm and rinse it with deionized water to remove surface impurities. Immerse the cut and rinsed titanium carrier completely in 20% NaOH solution and place it in a 75°C oil bath for heating treatment for 40 minutes, turning it over every 20 minutes to ensure uniform treatment. After the treatment is completed, take out the titanium carrier and rinse it thoroughly with deionized water. Subsequently, transfer the cleaned titanium carrier to a 15% oxalic acid solution and treat it in an 80°C oil bath for 40 minutes, turning it over every 20 minutes. After the treatment is completed, ultrasonically rinse the titanium carrier with deionized water to remove the oxalic acid solution remaining on the surface. Repeat the ultrasonic rinsing step twice until there is no obvious brown liquid seeping out of the cleaning solution.

[0087] (2) Preparation of sulfur precursor solution: 4.2 g SnCl4·5H2O, 250 mg SbCl3, and 271.9 mg NiCl2·6H2O were added to a mixed solution of 27 mL anhydrous ethanol and 3 mL concentrated hydrochloric acid in sequence. The mixed solution was ultrasonicated in an ultrasonicator for 30 min until all components were fully dissolved and a uniform and transparent precursor solution was formed.

[0088] (3) Hydrothermal sulfidation treatment: The pretreated titanium support was placed in the precursor solution prepared in step (2) and placed in a hydrothermal reactor for reaction at 180°C for 12 hours. After the reaction, the titanium support was cooled to room temperature. The hydrothermally treated titanium substrate was removed and repeatedly washed with distilled water and anhydrous ethanol. The resulting product was placed in a vacuum drying oven and dried at 70°C for 24 hours. After drying, the sample was placed in a muffle furnace and calcined at 500°C for 2 hours, with a heating rate set at 2°C / min.

[0089] The NATO / TiF electrode of Comparative Example 1 was used for electrolysis of water to produce ozone:

[0090] When the electrode prepared in Example 1 is used in the process of preparing the electrode anode, the added electrode in Example 1 is replaced with an electrode prepared in Comparative Example 1 of the same size, and the remaining operating conditions are the same as the experimental process of preparing ozone by electrolysis of water in Example 1.

[0091] The NATO / TiF electrode of Comparative Example 1 was used for chlorine evolution reaction:

[0092] When the electrode prepared in Example 1 is used in the process of preparing the electrode anode, the added electrode in Example 1 is replaced with an electrode prepared in Comparative Example 1 of the same size, and the remaining operating conditions are the same as the chlorine evolution experimental process in Example 1.

[0093] The concentration and Faraday efficiency of ozone produced by electrolysis of NATO / TiF electrode obtained in Comparative Example 1 under 0.5M H2SO4 are as follows: Figure 7 、 Figure 8 and Figure 10As shown, 500mA·cm -2 The accelerated life under current density is as follows Figure 9 As shown. Compared with Examples 1-5, it can be found that the initial concentration of the NATO / TiF electrode without sulfur doping can only reach 218ppm, but as the electrolysis time increases, the concentration decreases significantly, and the final concentration stabilizes at around 161ppm, the Faraday efficiency is only 9.8%, and the accelerated life time is only 146h. The DLS-NATO / TiF electrode prepared by doping sulfur and hydrothermal-calcination method in Example 1 shows better performance in the electrolysis reaction: its concentration at steady state is not much different from the initial concentration, and it can be maintained at a higher concentration (481ppm), Faraday efficiency (24.2%) and stability (the voltage remains stable within 900h). This shows that the catalyst loading of the electrode doped with sulfur is more stable, and the performance of ozone preparation (EOP) by electrolysis of water is significantly better than that of the electrode without sulfur doping.

[0094] The schematic diagram of the chlorine evolution reaction concentration and Faraday efficiency of the NATO / TiF electrode obtained in Comparative Example 1 under 1M NaCl (pH=2) is shown in FIG. Figure 11 and Figure 12 As shown, 250mA·cm -2 Stability test under current density such as Figure 13 Compared with Examples 1-5, the undoped sulfur electrode exhibited only 44.49 ppm and 66.31% effective chlorine concentration and Faraday efficiency, respectively, significantly lower than those of Examples 1-5 (sulfur-doped electrodes). Furthermore, the stability test duration was only 187 hours, significantly lower than that of Example 1 (400 hours). This further demonstrates that the sulfur-doped electrode catalyst exhibits superior CER performance.

[0095] Example 6

[0096] Performance impact of different sulfur source contents:

[0097] By changing the added mass of the sulfur source in Example 1 and keeping other operating conditions the same, the results show that disodium lauryl polyoxyethylene ether sulfosuccinate (DLS) has the best EOP / CER performance when used as the sulfur source. Figure 14 and Figure 15As shown. Comparative analysis found that the electrode with 100 mg of DLS added showed the best performance, with the Faradaic efficiency of EOP and CER reaching 24.2% and 95%, respectively, confirming that S-doped tin-antimony-nickel can effectively enhance the EOP and CER reaction activities. Further analysis of the amount of sulfur source added showed that when the sulfur source was too little, the degree of S element doping was insufficient, the number of active sites was limited, and the electrode surface reaction activity could not be fully improved; when the sulfur source was added too much, it may lead to S element enrichment and agglomeration, forming a non-uniform distribution, and even causing crystal structure defects and decreased electrode conductivity, which in turn inhibited the electrochemical activity. Therefore, reasonable control of the amount of sulfur source added is crucial to obtaining efficient and stable electrode performance.

[0098] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode, characterized in that: The following steps are involved: (1) Pretreatment of titanium support: The cut titanium support is sequentially rinsed with deionized water, alkali washed, acid washed, and ultrasonic washed; (2) Preparation of sulfur precursor solution: Add tin-containing compound, nickel-containing compound, antimony-containing compound and sulfur-containing surfactant to a mixed solvent of anhydrous ethanol and hydrochloric acid in sequence, and ultrasonicate for 10-30 minutes to mix them uniformly to obtain sulfur precursor solution A; (3) Hydrothermal sulfurization treatment: The sulfur precursor solution A prepared in step (2) and the titanium support pretreated in step (1) are placed in a hydrothermal kettle for hydrothermal reaction. After the reaction is completed, the titanium substrate is cooled to room temperature, and the hydrothermal titanium substrate is taken out and repeatedly washed with distilled water and anhydrous ethanol. The precursor material is obtained after vacuum drying. (4) Calcination treatment: The precursor material in step 3) is placed in a muffle furnace and calcined to obtain a three-dimensional porous sulfur-doped tin-antimony-nickel electrode.

2. The method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 1, characterized in that: Step (1) is specifically as follows: cutting the titanium support and rinsing it with deionized water to remove surface impurities, completely immersing the rinsed titanium support in a NaOH solution, and then placing it in an oil bath for heating for 30-60 minutes. After taking it out, rinsing the titanium substrate with deionized water, and then placing the washed titanium support in an oxalic acid solution and treating it in an oil bath for 30-60 minutes. After the treatment is completed, ultrasonically rinsing the titanium support with deionized water to remove the oxalic acid solution remaining on the surface. The ultrasonic rinsing step is repeated 2-4 times until no obvious brown liquid seeps out of the cleaning solution. Finally, the treated titanium support is placed in anhydrous ethanol for storage.

3. The method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 2, characterized in that: In step (1), the mass fraction of the NaOH solution is 15-30%, the mass fraction of the oxalic acid solution is 15-20%, and the temperature of the oil bath is 60-90°C.

4. The method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 1, characterized in that: In step (2), the tin-containing compound is one of tin tetrachloride pentahydrate, stannous nitrate, and stannous oxalate; the antimony-containing compound is one of antimony trioxide, antimony trichloride, and antimony pentoxide; the nickel-containing compound is one of nickel dichloride hexahydrate, nickel sulfide, nickel nitrate, and nickelous oxide; and the sulfur-containing surfactant is one of disodium lauryl polyoxyethylene ether sulfosuccinate, ammonium dodecylbenzenesulfonate, sodium p-toluenesulfonate, hexadecyltrimethylammonium p-toluenesulfonate, and sodium p-toluenesulfinate.

5. The method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 1, characterized in that: In step (2), the molar ratio of the added tin-containing compound, nickel-containing compound, and antimony-containing compound is 10-100:1-20:1-20, and the ratio of hydrochloric acid to anhydrous ethanol is 1:4-30.

6. The method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 1, characterized in that: In step (2), the concentration of the tin compound in the sulfur precursor solution A is 100 g / L-300 g / L, the concentration of the antimony compound is 1 g / L-10 g / L, the concentration of the nickel compound is 1 g / L-5 g / L, and the concentration of the sulfur-containing surfactant is 0.2 g / L-5 g / L.

7. The method for preparing a three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 1, characterized in that: In step (3), the hydrothermal temperature is 120-180°C, the time is 5-12h, and the vacuum drying temperature is 50-70°C, the time is 20-24h; in step (4), the muffle furnace roasting temperature is 400-600°C, the time is 1-3h, and the heating rate is 2-10°C / min.

8. A three-dimensional porous sulfur-doped tin-antimony-nickel electrode prepared by the preparation method according to any one of claims 1 to 7.

9. Use of the three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 8 in producing ozone by electrolysis of water, characterized in that: The current was controlled by a constant current meter, and a single electrolytic cell was used for the reaction. 0.5 MH2SO4 solution was used as the electrolyte, a three-dimensional porous sulfur-doped tin-antimony-nickel electrode was used as the working electrode, and a platinum sheet was used as the counter electrode. The reaction current density was controlled at 150-300 mA cm -2 , electrolyze water to produce ozone.

10. Use of the three-dimensional porous sulfur-doped tin-antimony-nickel electrode according to claim 8 in an electrochemical chlorine evolution reaction, characterized in that: The current was controlled by a constant current meter, and the reaction was carried out in an H-type electrolytic cell. A 1 M NaCl solution with a pH of 2 was used as the electrolyte. A three-dimensional porous sulfur-doped tin-antimony-nickel electrode was used as the working electrode, and a platinum sheet was used as the counter electrode. The reaction current density was controlled at 150-300 mA cm -2 , and carry out electrochemical chlorine evolution reaction.

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