A metal-doped titanium carbide composite material and its preparation method and application

Abstract

The present invention provides a metal-doped titanium carbide composite material, its preparation method, and application, belonging to the field of electrode material technology. The present invention utilizes physical vapor deposition of a carrier material to form a single-layer carbon-containing titanium coating; electrochemical oxidation and plasma etching are then sequentially performed, and finally, electrodeposition is performed in an electrolyte containing a metal salt to obtain the metal-doped titanium carbide composite material. The metal-doped titanium carbide composite material prepared by the present invention effectively solves the problem of poor selectivity and activity of the two-electron oxygen reduction reaction in impure water conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of electrode materials, and in particular to a metal-doped titanium carbide composite material and a preparation method and application thereof. Background Art

[0002] In recent years, hydrogen peroxide (H2O2) has been generated in situ by a two-electron oxygen reduction reaction and combined with ultraviolet (UV), ozone (O3) or Fe 2+ , which is used for water disinfection and removal of organic pollutants and has become a new green water treatment strategy.

[0003] Despite the many potential advantages of green electrosynthesis of hydrogen peroxide (H2O2) based on the two-electron oxygen reduction reaction, its actual production still faces several challenges, the most important of which is the selection and development of catalysts. Carbon-based materials have the advantages of large surface area, low price, strong conductivity, and high selectivity, and are widely used in the in situ electrosynthesis of hydrogen peroxide (H2O2). Furthermore, carbon-based materials can be modified by various methods, such as heteroatom doping, introduction of functional groups, pore control, and the construction of different morphologies or defects, to induce electron transfer to the active sites, significantly adjusting their catalytic performance.

[0004] However, due to the abundant pore structures of carbon-based catalysts, when used in water treatment, the active sites are easily clogged by adsorption of particulate matter, leading to irreversible degradation of the catalyst's activity. Therefore, the development of highly active and selective electrode materials capable of electrolyzing hydrogen peroxide (H2O2) in impure water (which has low conductivity and is more difficult to generate) is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a metal-doped titanium carbide composite material and its preparation method and application, so as to solve the problem of poor selectivity and activity of the two-electron oxygen reduction reaction under non-pure water conditions.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a metal-doped titanium carbide composite material, comprising the following steps:

[0008] Using Ti target as target material and hydrocarbon gas as working gas, the carrier material is subjected to physical vapor deposition to obtain a carbon-containing titanium layer material;

[0009] After electrochemically oxidizing the carbon-containing titanium layer material in an acid solution, the obtained material is subjected to plasma etching to obtain a defective titanium dioxide layer material;

[0010] The defect-containing titanium dioxide layer material is electro-deposited in an electrolyte containing a metal salt to obtain a metal-doped titanium carbide composite material.

[0011] Preferably, the purity of the Ti target is 90-99.99%; the hydrocarbon gas includes ethylene, acetylene or methane; and the reaction flow rate of the hydrocarbon gas is 50-1000 mL / min.

[0012] Preferably, the carrier material includes titanium sheet, titanium mesh, nickel mesh, copper mesh, titanium foam, iron foam, copper foam, nickel foam or stainless steel.

[0013] Preferably, the physical vapor deposition method includes magnetron sputtering or multi-arc ion plating;

[0014] The physical vapor deposition conditions include: argon as carrier gas, a reaction flow rate of 5 to 300 mL / min; a deposition temperature of 100 to 550° C.; a sputtering time of 30 to 240 min; and a sputtering thickness of 1 to 6 μm.

[0015] The coating in the carbon-titanium coating material is composed of titanium carbide or carbon-titanium carbide nanocomposite.

[0016] Preferably, the pH value of the acid solution is ≤7, and the acid in the acid solution includes sulfuric acid, nitric acid or hydrochloric acid; the voltage range of the electrochemical oxidation is -1.8 to 2V, the scanning rate is 10 to 150mV / s, and the number of scanning cycles is 5 to 100 cycles.

[0017] Preferably, the etching atmosphere of the plasma etching includes argon, hydrogen or nitrogen; the gas load of the plasma etching is 1 to 50 mL / min, the power is 100 to 800 W, the pressure is 20 to 150 Pa, and the irradiation time is 1 to 40 min.

[0018] Preferably, the metal in the metal salt includes one or more of platinum, palladium, gold, copper, mercury, manganese and silver; the total concentration of the metal salt in the electrolyte is 5 to 30 mmol / L; the electrolyte also includes a buffer and a conductive agent; the buffer includes boric acid, citric acid or phosphoric acid; the conductive agent includes at least one of sodium sulfate, sodium chloride, potassium chloride, ammonium chloride and potassium perchlorate; the molar concentration ratio of the metal salt, buffer and conductive agent is 5 to 30:30 to 250:180 to 900.

[0019] Preferably, the electrodeposition is carried out in a constant current electrodeposition manner; the electrodeposition temperature is 30 to 85° C., the current is 0.01 to 0.5 A, and the time is 10 to 150 min.

[0020] The present invention provides a metal-doped titanium carbide composite material prepared by the preparation method described in the above technical solution, comprising a carrier material and a metal-doped titanium carbide layer supported on the surface of the carrier material.

[0021] The present invention provides the use of the metal-doped titanium carbide composite material described in the above technical solution in preparing hydrogen peroxide by a two-electron oxygen reduction reaction.

[0022] The present invention uses physical vapor deposition to form a single-layer carbon-containing titanium coating on the surface of the carrier. The coating has excellent electrical conductivity, good electrochemical stability and physicochemical stability. It can generate abundant oxygen vacancy active sites while improving the good electrical conductivity of the catalyst, ensuring that its surface layer allows sufficient electrolyte diffusion, providing more catalytic active sites for the two-electron oxygen reduction reaction, thereby improving the activity and selectivity of the composite material. The present invention uses an electrochemical oxidation process to generate a titanium dioxide layer on the surface of the single-layer carbon-containing titanium coating, and uses plasma etching to further generate oxygen vacancies. The titanium dioxide layer can increase stability and facilitate the subsequent etching process to generate oxygen vacancies. The intrinsic effect of oxygen vacancies effectively promotes the adsorption and activation of O2 and H2O reactants and reaction intermediates, thereby improving the catalytic activity of the material. Finally, the present invention uses metal loading to further effectively promote the transfer of charge, thereby greatly reducing the reaction energy barrier and promoting molecular activation, thereby making the electrode kinetics easier, thereby effectively solving the problem of poor selectivity and activity of the two-electron oxygen reduction reaction under non-pure water conditions.

[0023] The metal-doped titanium carbide composite material prepared by the present invention undergoes a two-electron oxygen reduction reaction in a non-pure water system (such as tap water) to produce hydrogen peroxide, which provides a new idea for solving the problem that when carbon-based catalysts are used for water treatment, the active sites are easily blocked due to the adsorption of particulate matter, thereby causing irreversible attenuation of the catalyst activity. Compared with existing carbon-based materials, when the metal-doped titanium carbide composite material prepared by the present invention is applied to non-pure water, most of the particulate matter adsorbed on the surface is hydroxide. The adsorbed particulate matter can be removed by using a weak acid reaction such as citric acid or by polarity reversal, thereby re-exposing the surface active sites and achieving reversible activity. However, the pores of existing carbon-based materials are relatively dense, cannot be completely removed, and are prone to carbon corrosion. Therefore, after the carbon material adsorbs particulate matter, its activity is an irreversible attenuation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a SEM characterization image of the titanium carbide layer material in Example 1;

[0025] Figure 2 This is the XRD characterization diagram of the titanium carbide layer material in Example 1;

[0026] Figure 3This is a cyclic voltammetry scan of the electro-oxidation process of the titanium carbide layer material in Example 1;

[0027] Figure 4 A graph showing the concentration and Faraday efficiency of H2O2 produced by the metal-doped titanium carbide composite materials prepared in Example 1 and Example 2 under non-pure water conditions;

[0028] Figure 5 The graph is a graph showing the concentration of H2O2 generated by the composite materials prepared in Example 1 and Comparative Example 1 under non-pure water conditions and the Faradaic efficiency. DETAILED DESCRIPTION

[0029] The present invention provides a method for preparing a metal-doped titanium carbide composite material, comprising the following steps:

[0030] Using Ti target as target material and hydrocarbon gas as working gas, the carrier material is subjected to physical vapor deposition to obtain a carbon-containing titanium layer material;

[0031] After electrochemically oxidizing the carbon-containing titanium layer material in an acid solution, the obtained material is subjected to plasma etching to obtain a defective titanium dioxide layer material;

[0032] The defect-containing titanium dioxide layer material is electro-deposited in an electrolyte containing a metal salt to obtain a metal-doped titanium carbide composite material.

[0033] In the present invention, unless otherwise specified, the raw materials required for preparation are all commercially available products well known to those skilled in the art.

[0034] The present invention uses a Ti target as a target material and a hydrocarbon gas as a working gas to perform physical vapor deposition on a carrier material to obtain a carbon-containing titanium layer material.

[0035] In the present invention, the purity of the Ti target is preferably 90-99.99%; the hydrocarbon gas preferably includes ethylene, acetylene or methane; the reaction flow rate of the hydrocarbon gas is preferably 50-1000 mL / min, more preferably 60-900 mL / min, and further preferably 200-800 mL / min.

[0036] In the present invention, the carrier material preferably includes titanium sheet, titanium mesh, nickel mesh, copper mesh, titanium foam, iron foam, copper foam, nickel foam, or stainless steel, more preferably titanium sheet, titanium mesh, nickel mesh, copper mesh, titanium foam, copper foam, nickel foam, or stainless steel, further preferably titanium sheet, titanium mesh, nickel mesh, copper mesh, titanium foam, nickel foam, or stainless steel. The present invention has no particular limitation on the size of the carrier material and can be adjusted according to actual needs.

[0037] In the present invention, the support material is preferably pretreated before physical vapor deposition. The pretreatment preferably comprises: sanding the support material, sequentially placing it in acetone, hydrochloric acid (at a concentration of 5-8 wt%), ethanol, and water, ultrasonically treating it, and drying it to obtain the pretreated support material. The present invention does not specifically limit the sanding and ultrasonication conditions, and they can be adjusted according to actual needs.

[0038] In the present invention, the physical vapor deposition is preferably carried out in a vacuum environment; the method of the physical vapor deposition preferably includes magnetron sputtering or multi-arc ion plating; the conditions of the physical vapor deposition preferably include: the carrier gas is argon, the reaction flow rate is 5 to 300 mL / min, more preferably 10 to 250 mL / min, and further preferably 50 to 200 mL / min; the deposition temperature is 100 to 550°C, more preferably 200 to 450°C, and further preferably 300 to 350°C; the sputtering time is 30 to 240 min, more preferably 40 to 200 min, and further preferably 60 to 180 min; the sputtering thickness is 1 to 6 μm, more preferably 2 to 5 μm, and further preferably 3 to 4 μm.

[0039] After the physical vapor deposition is completed, the present invention preferably cools to room temperature and performs electrochemical oxidation.

[0040] In the present invention, the coating in the carbon-titanium coating material is composed of titanium carbide or carbon-titanium carbide nanocomposite.

[0041] The present invention obtains titanium carbide or carbon-titanium carbide nanocomposite by regulating the deposition parameters of physical vapor deposition, and controls the above physical vapor deposition parameters so that sp 3 The content is less than sp 2 The content of titanium carbide is then partially oxidized to form titanium dioxide through a subsequent electrochemical oxidation process. At the same time, carbon is also oxidized, thereby grafting other functional groups such as hydroxyl and carboxyl groups. Then, oxygen vacancies are generated through plasma etching, thereby increasing the activity. The present invention avoids the sp during the deposition of carbon-titanium carbide materials by regulating the physical vapor deposition parameters. 3 Content greater than sp 2 The carbon content leads to a decrease in conductivity, thereby affecting the reaction activity, and at the same time avoids excessive carbon in the carbon-titanium carbide material causing a decrease in the quality of the coating due to carbon corrosion during the oxidation process.

[0042] After obtaining the carbon-containing titanium layer material, the present invention electrochemically oxidizes the carbon-containing titanium layer material in an acid solution, and then plasma etches the obtained material to obtain a defect-containing titanium dioxide layer material.

[0043] In the present invention, the pH value of the acid solution is preferably ≤7, and the acid in the acid solution preferably includes sulfuric acid, nitric acid or hydrochloric acid; the acid solution is preferably an aqueous solution of the corresponding acid.

[0044] In the present invention, the voltage range of the electrochemical oxidation is preferably -1.8 to 2 V, more preferably -1.5 to 1.9 V, and more preferably -1.0 to 1.8 V; the scan rate is preferably 10 to 150 mV / s, more preferably 20 to 120 mV / s, and more preferably 50 to 100 mV / s; the number of scan cycles is preferably 5 to 100 cycles, more preferably 30 to 90 cycles, and more preferably 40 to 80 cycles.

[0045] In the present invention, the counter electrode used in the electrochemical oxidation is preferably a graphite rod electrode, the reference electrode used is preferably a saturated calomel electrode, and the working electrode used is preferably a carbon-containing titanium layer material; during the electrochemical oxidation process, titanium carbide is covered on the surface of the support material in a spherical structure, and is in situ converted into a titanium dioxide layer on the surface of the titanium carbide through electrochemical oxidation, forming a titanium carbide@titanium dioxide core-shell structure.

[0046] After the electrochemical oxidation is completed, the obtained material is placed in water for cleaning, dried, and then subjected to plasma etching.

[0047] In the present invention, the etching atmosphere of the plasma etching preferably includes argon, hydrogen or nitrogen; the gas load of the plasma etching is 1 to 50 mL / min, more preferably 8 to 40 mL / min, and further preferably 10 to 30 mL / min; the power is 100 to 800 W, more preferably 150 to 700 W, and further preferably 200 to 600 W; the pressure is preferably 20 to 150 Pa, more preferably 30 to 140 Pa, and further preferably 40 to 100 Pa; the irradiation time is preferably 1 to 40 min, more preferably 5 to 35 min, and further preferably 10 to 30 min. The present invention strips oxygen from the titanium dioxide layer by plasma etching to form oxygen vacancies, thereby producing a defective titanium dioxide layer material with oxygen vacancies.

[0048] After obtaining the defective titanium dioxide layer material, the present invention performs electrodeposition on the defective titanium dioxide layer material in an electrolyte containing a metal salt to obtain a metal-doped titanium carbide composite material.

[0049] In the present invention, the metal in the metal salt preferably includes one or more of platinum, palladium, gold, copper, mercury, manganese and silver; the anion of the metal salt is preferably one or more of chloride ion, nitrate ion and sulfate ion; when the metal is two or more of the above, the present invention has no special limitation on the ratio of different types of metals, and can be adjusted according to actual needs.

[0050] In the present invention, the total concentration of the metal salt in the electrolyte is preferably 5 to 30 mmol / L, more preferably 6 to 28 mmol / L, and further preferably 7 to 25 mmol / L; the solvent used in the electrolyte is preferably water; the electrolyte preferably also includes a buffer and a conductive agent; the buffer preferably includes boric acid, citric acid or phosphoric acid; the conductive agent preferably includes at least one of sodium sulfate, sodium chloride, potassium chloride, ammonium chloride and potassium perchlorate; when the conductive agent is two or more of the above, the present invention has no special limitation on the ratio of different types of conductive agents, and can be adjusted according to actual needs.

[0051] In the present invention, the molar concentration ratio of the metal salt, buffer and conductive agent is preferably 5-30:30-250:180-900, more preferably 6-25:100-220:200-850, and further preferably 8-20:160-200:500-800.

[0052] In the present invention, in the electrodeposition, the graphite sheet serves as the anode and the defective titanium dioxide layer material serves as the cathode.

[0053] The deposition method of the electrodeposition is preferably constant current electrodeposition; the temperature of the electrodeposition is preferably 30-85°C, more preferably 35-80°C, and more preferably 45-75°C; the current is preferably 0.01-0.5A, more preferably 0.02-0.45A, and more preferably 0.04-0.4A; the time is preferably 10-150min, more preferably 20-130min, and more preferably 60-120min.

[0054] After the electrodeposition is completed, the obtained material is washed with water to obtain a metal-doped titanium carbide composite material.

[0055] The present invention provides a metal-doped titanium carbide composite material prepared by the preparation method described in the above technical solution, comprising a carrier material and a metal-doped titanium carbide layer supported on the surface of the carrier material.

[0056] The present invention provides the use of the metal-doped titanium carbide composite material described in the above technical solution in the preparation of hydrogen peroxide by a two-electron oxygen reduction reaction. The present invention does not specifically limit the method of the application, and the application can be carried out according to methods well known in the art.

[0057] The technical solutions provided by the present invention are described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0058] Example 1

[0059] The stainless steel carrier material was polished with 200-mesh, 1200-mesh and 4000-mesh sandpaper in sequence, and then placed in acetone, hydrochloric acid (8wt%), ethanol and water for ultrasonic treatment. After drying, the stainless steel carrier material was placed in a vacuum environment for magnetron sputtering. The reaction conditions were: pure Ti target with a purity of 99.99%; argon as carrier gas with a reaction flow rate of 50 mL / min; acetylene as working gas with a reaction flow rate of 200 mL / min; deposition temperature of 350°C; sputtering time of 60 min, to obtain a titanium carbide layer material with a sputtering thickness of 3 μm. , cooled to room temperature, placed in a 0.1M sulfuric acid aqueous solution (pH = 1) for electrochemical oxidation process, set a graphite rod electrode as the counter electrode, a saturated calomel electrode as the reference electrode, the scanning voltage range is -1.0 to 1.8V, the scanning rate is 100mV / s, and the number of scanning circles is 30 circles. After the end, the obtained material is washed with water and dried; after the drying, the sample is placed in a hydrogen atmosphere for plasma etching process, the gas load is 10mL / min, the power is set to 600W, the pressure is 40Pa, and the irradiation time is 30min to obtain a defect-containing titanium dioxide layer material;

[0060] Water was used to prepare an electrolyte containing metal salts, so that the concentrations of its components were 20 mmol / L potassium chloroplatinate, 5 mmol / L potassium chloropalladate, 100 mmol / L citric acid, and 200 mmol / L potassium perchlorate, respectively. A graphite sheet was used as the anode, and the prepared double-layer coating containing defective titanium dioxide was used as the cathode. Electrodeposition was carried out at a temperature of 50°C and a current of 0.02 A for 10 minutes. After the deposition, the obtained material was washed with water to obtain a metal-doped titanium carbide composite material.

[0061] Example 2

[0062] The titanium mesh carrier material was polished with 400 mesh, 1000 mesh and 5000 mesh sandpaper in sequence, and then placed in acetone, hydrochloric acid (5wt%), ethanol and water for ultrasonic treatment. After drying, the titanium mesh carrier material was placed in a vacuum environment for multi-arc ion plating. The reaction conditions were: pure Ti target with a purity of 99.99%; argon as carrier gas with a reaction flow rate of 200 mL / min; methane as working gas with a reaction flow rate of 1000 mL / min; deposition temperature of 300°C; sputtering time of 40 min to obtain a carbon-carbonized film with a sputtering thickness of 4 μm. The titanium nanocomposite layer material is cooled to room temperature and placed in a 5M sulfuric acid aqueous solution for an electrochemical oxidation process, with a graphite rod electrode as a counter electrode and a saturated calomel electrode as a reference electrode. The scanning voltage range is -1.0 to 1.8 V, the scanning rate is 50 mV / s, and the number of scanning cycles is 40. After the end, the obtained sample is washed with water and dried. After drying, the sample is placed in a hydrogen atmosphere for plasma etching with a gas load of 8 mL / min, a power of 200 W, a pressure of 100 Pa, and an irradiation time of 40 minutes to obtain a defective titanium dioxide layer material;

[0063] Water was used to prepare an electrolyte containing metal salts, so that the concentrations of its components were 10 mmol / L potassium chloroplatinate, 10 mmol / L potassium chloropalladate, 160 mmol / L boric acid, and 500 mmol / L potassium chloride, respectively. A graphite sheet was used as the anode, and the prepared defective titanium dioxide layer material was used as the cathode. Electrodeposition was carried out at a temperature of 45°C and a current of 0.04 A for 60 minutes. After the deposition was completed, the obtained material was washed with water to obtain a metal-doped titanium carbide composite material.

[0064] Comparative Example 1

[0065] The titanium mesh carrier material was polished with 400-mesh, 2000-mesh, and 5000-mesh sandpaper in sequence, and then placed in acetone, hydrochloric acid (8 wt%), ethanol, and water for ultrasonic treatment. After drying, the titanium mesh carrier material was placed in a vacuum environment for multi-arc ion plating. The reaction conditions were pure Cr target with a purity of 99.99%; argon was the carrier gas with a reaction flow rate of 200 mL / min; methane was the working gas with a reaction flow rate of 800 mL / min; the deposition temperature was 400°C; the sputtering time was 30 min. A titanium carbide nanolayer material with a sputtering thickness of 3 μm was obtained, cooled to room temperature, and placed in a 1M sulfuric acid solution for an electrochemical oxidation process. A graphite rod electrode was set as a counter electrode, a saturated calomel electrode was set as a reference electrode, the voltage was -1.0 to 1.8 V, and the scanning rate was 50 mV / s. After the end, the obtained sample was washed with water and dried; after drying, the sample was placed in an argon atmosphere for plasma etching, the power was set to 150 W, the pressure was 20 Pa, and the radiation time was 35 min to obtain a defective titanium dioxide layer material.

[0066] Characterization and testing

[0067] 1) The titanium carbide layer material prepared in Example 1 was characterized by SEM, and the results were as follows: Figure 1 shown; from Figure 1 It can be seen that the titanium carbide layer obtained by magnetron sputtering is formed by stacking several balls, which is greatly beneficial to increase the specific surface area and provide abundant diffusion channels for the desorption and discharge of hydrogen peroxide in the two-electron oxygen reduction process.

[0068] 2) The titanium carbide layer material prepared in Example 1 was subjected to XRD characterization, and the results were as follows: Figure 2 shown; from Figure 2 It can be seen that the 2θ of the titanium carbide layer obtained by magnetron sputtering are located at 35.72°, 41.51°, 60.41°, and 74.52°, respectively, which belong to the characteristic diffraction peaks of titanium carbide, corresponding to the standard card titanium carbide JCPDSno.71-0298; and the characteristic diffraction peaks at 43.46°, 44.37°, 50.62°, 72.01°, and 76.11° correspond to the characteristic diffraction peaks of the stainless steel carrier material, indicating that titanium carbide is successfully formed on the surface of the stainless steel carrier material by magnetron sputtering.

[0069] 3) The titanium carbide layer material prepared in Example 1 was subjected to cyclic voltammetry scanning during the electro-oxidation process. A graphite rod electrode was set as the counter electrode, a saturated calomel electrode was set as the reference electrode, the scanning voltage was -1.0 to 1.8 V, the scanning rate was 100 mV / s, and the number of scanning cycles was 30. The cyclic voltammetry of the electro-oxidation process is shown in FIG. Figure 3 shown; from Figure 3 As can be seen in the figure, the first scan produces oxidation peaks at 0.97V and 1.56V, respectively, followed by a slight reduction; however, as the number of scans continues to increase, the oxidation peaks gradually disappear or even completely disappear. This indicates that the initial oxidation in the first scan irreversibly oxidizes titanium carbide to titanium dioxide.

[0070] 4) The metal-doped titanium carbide composite materials prepared in Examples 1 and 2 and the material prepared in Comparative Example 1 were respectively used to prepare H2O2. The relationship between the concentration and time of H2O2 produced under the conditions of no diaphragm and non-pure water is shown in the following figure: Figures 4-5 shown by Figure 4 It can be seen that the metal-doped titanium carbide composite material prepared in Example 1 can produce 18 mg / L H2O2 in 20 minutes under the conditions of no diaphragm and tap water, and the Faraday efficiency reaches 97.31%; the metal-doped titanium carbide composite material prepared in Example 2 can produce 14 mg / L H2O2 in 20 minutes under the conditions of no diaphragm and tap water, and the Faraday efficiency is 75.68%.

[0071] Depend on Figure 5 It can be seen that the oxygen reduction electrode material prepared in Comparative Example 1 produces 6 mg / L H2O2 in 20 minutes under the conditions of no diaphragm and tap water, and the Faradaic efficiency is 37.84%.

[0072] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a metal-doped titanium carbide composite material, characterized in that: The following steps are involved: Using Ti target as target material and hydrocarbon gas as working gas, the carrier material is subjected to physical vapor deposition to obtain a carbon-containing titanium layer material; After electrochemically oxidizing the carbon-containing titanium layer material in an acid solution, the obtained material is subjected to plasma etching to obtain a defective titanium dioxide layer material; The defect-containing titanium dioxide layer material is electro-deposited in an electrolyte containing a metal salt to obtain a metal-doped titanium carbide composite material.

2. The preparation method according to claim 1, characterized in that The purity of the Ti target is 90-99.99%; the hydrocarbon gas includes ethylene, acetylene or methane; and the reaction flow rate of the hydrocarbon gas is 50-1000 mL / min.

3. The preparation method according to claim 1, characterized in that The carrier material includes titanium sheet, titanium mesh, nickel mesh, copper mesh, foamed titanium, foamed iron, foamed copper, foamed nickel or stainless steel.

4. The preparation method according to claim 1, characterized in that The physical vapor deposition method includes magnetron sputtering or multi-arc ion plating; The physical vapor deposition conditions include: argon as carrier gas, a reaction flow rate of 5 to 300 mL / min; a deposition temperature of 100 to 550° C.; a sputtering time of 30 to 240 min; and a sputtering thickness of 1 to 6 μm. The middle layer of the carbon-titanium layer material is composed of titanium carbide or carbon-titanium carbide nanocomposite.

5. The preparation method according to claim 1, characterized in that The pH value of the acid solution is ≤7, and the acid in the acid solution includes sulfuric acid, nitric acid or hydrochloric acid; the voltage range of the electrochemical oxidation is -1.8 to 2V, the scanning rate is 10 to 150mV / s, and the number of scanning circles is 5 to 100 circles.

6. The preparation method according to claim 1, characterized in that The etching atmosphere of the plasma etching includes argon, hydrogen or nitrogen; the gas load of the plasma etching is 1 to 50 mL / min, the power is 100 to 800 W, the pressure is 20 to 150 Pa, and the irradiation time is 1 to 40 min.

7. The preparation method according to claim 1, characterized in that The metal in the metal salt includes one or more of platinum, palladium, gold, copper, mercury, manganese and silver; the total concentration of the metal salt in the electrolyte is 5 to 30 mmol / L; the electrolyte also includes a buffer and a conductive agent; the buffer includes boric acid, citric acid or phosphoric acid; the conductive agent includes at least one of sodium sulfate, sodium chloride, potassium chloride, ammonium chloride and potassium perchlorate; the molar concentration ratio of the metal salt, buffer and conductive agent is 5 to 30:30 to 250:180 to 900.

8. The preparation method according to claim 1 or 7, characterized in that The electrodeposition method is constant current electrodeposition; the electrodeposition temperature is 30-85° C., the current is 0.01-0.5A, and the time is 10-150 minutes.

9. The metal-doped titanium carbide composite material prepared by the preparation method according to any one of claims 1 to 8, characterized in that: The invention comprises a carrier material and a metal-doped titanium carbide layer supported on the surface of the carrier material.

10. Use of the metal-doped titanium carbide composite material according to claim 9 in preparing hydrogen peroxide by a two-electron oxygen reduction reaction.

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