WO2022213663A1 - 一种BiVO4/CoP薄膜电极及其制备方法和应用 - Google Patents

一种BiVO4/CoP薄膜电极及其制备方法和应用 Download PDF

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WO2022213663A1
WO2022213663A1 PCT/CN2021/139658 CN2021139658W WO2022213663A1 WO 2022213663 A1 WO2022213663 A1 WO 2022213663A1 CN 2021139658 W CN2021139658 W CN 2021139658W WO 2022213663 A1 WO2022213663 A1 WO 2022213663A1
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bivo
electrode
cop
thin film
photoelectrode
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French (fr)
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熊贤强
张晓�
褚雨潇
武承林
吴琛琦
张川群
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台州学院
台州市生物医化产业研究院有限公司
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F13/00—Inhibiting corrosion of metals by anodic or cathodic protection
    • C23F13/02—Inhibiting corrosion of metals by anodic or cathodic protection cathodic; Selection of conditions, parameters or procedures for cathodic protection, e.g. of electrical conditions
    • C23F13/06—Constructional parts, or assemblies of cathodic-protection apparatus
    • C23F13/08—Electrodes specially adapted for inhibiting corrosion by cathodic protection; Manufacture thereof; Conducting electric current thereto
    • C23F13/12—Electrodes characterised by the material

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  • the invention belongs to the technical field of metal anticorrosion, and in particular relates to a BiVO 4 /CoP thin film electrode and a preparation method and application thereof.
  • Metal materials are one of the longest-used materials in human history. They are widely used as structural materials and functional materials in the fields of industry, agricultural production and scientific research. However, the thermodynamically unstable state of metal makes it inevitable to have a tendency to corrode during use. Metal corrosion is very destructive.
  • metal anti-corrosion technology can be divided into two categories: physical barrier protection and electrochemical protection methods.
  • Physical barrier protection prevents the metal from chemically reacting with these substances by coating the surface of the metal substrate with a passivation layer to prevent the contact and penetration of oxygen, water, and salts.
  • the principle of electrochemical protection is to change the potential of metal products by applying an electric current, thereby slowing down or inhibiting the corrosion of metal products.
  • Electrochemical protection is divided into two types, namely anodic protection and cathodic protection. Among them, photocathodic protection is a new type of cathodic protection technology. It does not use anti-corrosion materials as sacrificial agents and does not need to consume anti-corrosion materials. It only uses green and clean solar energy to slow down or even inhibit the corrosion of metal materials and achieve permanent protection.
  • Photocathode protection mainly realizes metal anticorrosion through metal and photoelectrode (prepared from semiconductor materials), and uses the effect of semiconductor coating to generate photogenerated electron-hole pairs under the condition of light irradiation, and transfers the photogenerated electrons generated by the excitation of semiconductor coating by light. to the base metal material, thereby realizing the protection of the base metal.
  • photocathode protection technology it is particularly important to find more effective semiconductor materials. So far, many semiconductors have been widely developed, such as TiO 2 , SnO 2 , ⁇ -Fe 2 O 3 /Fe 3 O 4 , BiVO 4 , etc., which can provide enough electrons for metal materials to slow down or prevent oxidation reactions .
  • BiVO 4 has a suitable band gap structure (Eg ⁇ 2.4 eV), which can drive the water oxidation reaction under visible light driving, and also has a relatively negative conduction band potential, which is thermodynamically favorable for electron transfer to the protective metal.
  • the BiVO4 photoelectrode has poor water oxidation activity and high electron-hole recombination rate, and it is difficult for photogenerated electrons to transfer from the BiVO4 photoelectrode to the protected metal at open circuit potential, thus limiting the photogenerated cathodic protection ability of metals.
  • BiVO 4 photoelectrode has low stability and is prone to chemical corrosion and photocorrosion, and its application in photogenerated cathode anticorrosion is not stable.
  • the purpose of the present invention is to provide a BiVO 4 /CoP thin film electrode and a preparation method and application thereof.
  • the BiVO 4 /CoP thin film electrode provided by the present invention has good water oxidation activity, good chemical corrosion resistance and photocorrosion resistance, and is suitable for anticorrosion of photogenerated cathodes. The stability of the application is good.
  • the present invention provides the following technical solutions:
  • the invention provides a preparation method of BiVO 4 /CoP thin film electrode, comprising the following steps: mixing acetate, hypophosphite, soluble cobalt salt and a solvent to obtain a mixed electrolyte solution;
  • the BiVO 4 photoelectrode is placed in the mixed electrolyte solution, the BiVO 4 photoelectrode is used as the working electrode, and a three-electrode system is used for cyclic voltammetric electrodeposition, and a CoP promoter layer is formed on the surface of the BiVO 4 photoelectrode to obtain BiVO 4 /CoP thin film electrodes.
  • the concentration of acetate in the mixed electrolyte solution is 0.5-5 mol/L
  • the concentration of hypophosphite is 0.01-0.5 mol/L
  • the concentration of soluble cobalt salt is 0.02-1 mol/L.
  • the counter electrode of the three-electrode system is a platinum mesh electrode
  • the reference electrode is a silver chloride electrode
  • the conditions for the cyclic voltammetric electrodeposition include: a scan rate of 50-200 mV/s, a potential range of -0.9-0 V, and a cycle number of 3-100 times.
  • the BiVO 4 photoelectrode includes a substrate and a BiVO 4 thin film supported on the surface of the substrate; the BiVO 4 thin film has a thickness of 500-1000 nm.
  • the BiVO 4 thin film is formed of BiVO 4 nanoparticles; the BiVO 4 nanoparticles have a particle size of 100-200 nm.
  • the present invention also provides the BiVO 4 /CoP thin film electrode prepared by the above preparation method.
  • the BiVO 4 /CoP thin film electrode comprises a BiVO 4 photoelectrode and a CoP promoter layer supported on the surface of the BiVO 4 photoelectrode.
  • the thickness of the CoP promoter layer is 2-50 nm.
  • the present invention also provides the application of the BiVO 4 /CoP thin film electrode described in the above scheme in the anticorrosion of the photocathode.
  • the cathode metal materials in the application are stainless steel, carbon steel and titanium plates.
  • the invention provides a preparation method of BiVO 4 /CoP thin film electrode, comprising the following steps: mixing sodium acetate, sodium hypophosphite, cobalt acetate and a solvent to obtain a mixed electrolyte solution; placing the BiVO 4 photoelectrode in the mixed electrolyte solution Among them, BiVO 4 photoelectrode was used as the working electrode, and a three-electrode system was used for cyclic voltammetric electrodeposition to obtain BiVO 4 /CoP thin film electrodes.
  • V 5+ on BiVO 4 is electro-reduced to V 4+ through cyclic voltammetric electrodeposition, and then oxygen vacancies are introduced on the surface of BiVO 4.
  • Co 2+ and H 2 PO 2- in the solution are converted into CoP is deposited on the outer layer of BiVO 4 , which improves the hole transfer efficiency of BiVO 4 through the introduction of oxygen vacancies and the loading of CoP, increases the reaction rate of water oxidation, significantly reduces the activation energy of water oxidation, and improves the current carrying capacity of BiVO 4 photoelectrode Therefore, the recombination rate of photogenerated electrons and holes is suppressed, and the effective water splitting on the electrode surface is realized under the driving condition of visible light, which directly makes the photogenerated electrons gather on the photoelectrode FTO substrate, and drives the photogenerated electrons to effectively transfer to the protected area. Metal, to achieve open circuit potential effective photocathode corrosion protection.
  • the CoP layer deposited on the outer layer of BiVO 4 and the abundant oxygen vacancies can effectively improve the chemical corrosion resistance and photocorrosion resistance of the BiVO 4 layer under the synergistic effect, ensuring that the BiVO 4 photoelectrode can be stably used in photocathode anticorrosion.
  • Fig. 1 is the X-ray diffraction pattern of BiVO 4 , BiVO 4 /CV and BiVO 4 /CoP thin film electrodes prepared in Example 1;
  • Fig. 2 is the Co element XPS image of the BiVO 4 /CoP thin film electrode prepared in Example 1;
  • Fig. 3 is the P element XPS diagram of the BiVO 4 /CoP thin film electrode prepared in Example 1;
  • Example 4 is a scanning electron microscope image of the BiVO 4 /CoP thin film electrode prepared in Example 2;
  • Fig. 5 is the scanning electron microscope picture of BiVO photoelectrode prepared in embodiment 2 ;
  • Example 7 is a photocurrent-time graph of BiVO 4 photoelectrode, BiVO 4 /CV thin film electrode and BiVO 4 /CoP thin film electrode under visible light irradiation in Example 3;
  • Fig. 8 is the open circuit potential-time curve diagram of BiVO 4 -304 stainless steel coupling electrode, BiVO 4 /CV-304 stainless steel coupling electrode and BiVO 4 /CoP-304 stainless steel coupling electrode in dark state and light in Example 4;
  • the invention provides a preparation method of BiVO 4 /CoP thin film electrode, comprising the following steps:
  • the BiVO 4 photoelectrode was placed in the mixed electrolyte solution, the BiVO 4 photoelectrode was used as the working electrode, and a three-electrode system was used for cyclic voltammetric electrodeposition, and a CoP cocatalyst layer was formed on the surface of the BiVO 4 photoelectrode to obtain BiVO 4 /CoP Thin film electrodes.
  • acetate, hypophosphite, soluble cobalt salt and solvent are mixed to obtain a mixed electrolyte solution.
  • the acetate preferably includes sodium acetate, potassium acetate, more preferably sodium acetate
  • the hypophosphite preferably includes sodium hypophosphite
  • the soluble cobalt salt preferably includes cobalt acetate
  • the solvent It is preferably water, more preferably ultrapure water; the above-mentioned mixing process can adopt mixing methods well known to those skilled in the art, such as stirring mixing and ultrasonic mixing.
  • the concentration of acetate in the mixed electrolyte solution is preferably 0.5-5 mol/L, more preferably 1.5-4 mol/L, more preferably 2-3.5 mol/L, most preferably 3 mol/L
  • the concentration of hypophosphite is preferably 0.01-0.5mol/L, more preferably 0.05-0.4mol/L, more preferably 0.1-0.3mol/L, most preferably 0.2mol/L
  • the concentration of soluble cobalt salt is preferably 0.02 to 1 mol/L, more preferably 0.04 to 0.9 mol/L, more preferably 0.1 to 0.8 mol/L, and most preferably 0.5 mol/L.
  • the concentration of each substance in the mixed electrolyte solution is controlled within the above range, which can avoid the increase of the degree of side reactions caused by the high concentration of the electrolyte solution, increase the impurity components of the prepared thin film electrode, and avoid the concentration of the mixed electrolyte solution at the same time. If it is too low, the subsequent cyclic voltammetric electrodeposition reaction cannot proceed, and the BiVO 4 /CoP thin film electrode cannot be obtained in the end.
  • the present invention places the BiVO 4 photoelectrode in the mixed electrolyte solution, uses the BiVO 4 photo electrode as the working electrode, adopts a three-electrode system for cyclic voltammetry electrodeposition, and forms a CoP promoter layer on the surface of the BiVO 4 photoelectrode , the BiVO 4 /CoP thin film electrode was obtained.
  • the three-electrode system uses a BiVO 4 photoelectric electrode as the working electrode, the counter electrode is preferably a platinum mesh electrode, and the reference electrode is preferably a silver chloride electrode.
  • the working electrode is preferably a platinum mesh electrode
  • the reference electrode is preferably a silver chloride electrode.
  • the BiVO 4 photoelectrode comprises a substrate and a BiVO 4 film supported on the surface of the substrate; the thickness of the BiVO 4 film is preferably 500-1000 nm, and the substrate is preferably a FTO glass substrate; the BiVO 4 The thin film is preferably formed of BiVO 4 nanoparticles; the particle size of the BiVO 4 nanoparticles is preferably 100-200 nm.
  • the source of the BiVO 4 photoelectrode is not particularly limited in the present invention, and can be prepared by a method well known to those skilled in the art; in a specific embodiment of the present invention, the preparation method of the BiVO 4 photoelectrode preferably includes the following steps :
  • a soluble bismuth source and a KI solution are mixed to obtain a bismuth source potassium iodide mixed solution.
  • the soluble bismuth source is preferably bismuth nitrate; the concentration of the potassium iodide solution is preferably 0.1-1 mol/L, more preferably 0.2-0.6 mol/L, and the pH value of the potassium iodide solution is preferably 1- 2, more preferably 1.7.
  • the mixing method is preferably ultrasonic mixing; the power of the ultrasonic mixing is preferably 200-600W, more preferably 300-500W; the time is preferably 1-6h, more preferably 2-4h; the present invention
  • the soluble bismuth source was completely dissolved in the KI solution by the ultrasonic mixing.
  • the concentration of the bismuth source in the bismuth source potassium iodide mixed solution is preferably 0.01-0.2 mol/L, more preferably 0.02-0.1 mol/L.
  • the present invention mixes p-benzoquinone with ethanol to obtain p-benzoquinone ethanol solution.
  • the concentration of p-benzoquinone in the p-benzoquinone ethanol solution is preferably 0.1-1 mol/L, more preferably 0.2-0.6 mol/L.
  • the mixing method is preferably ultrasonic mixing; the power of the ultrasonic mixing is preferably 200-600W, more preferably 300-500W; the time is preferably 0.5-3h, more preferably 0.5-1h; the present invention By the ultrasonic mixing, p-benzoquinone was completely dissolved in ethanol.
  • the present invention mixes the bismuth source potassium iodide mixed solution and the p-benzoquinone ethanol solution with ultrasonic treatment to obtain an electrolyte solution.
  • the power of the ultrasonic treatment is preferably 200-600W, more preferably 300-500W, and the time of the ultrasonic treatment is preferably 20min.
  • the present invention places the substrate in the electrolyte, uses the substrate as a working electrode, uses a three-electrode system for photoelectric deposition, and forms a BiOI film on the surface of the substrate to obtain a BiOI photoelectrode.
  • the substrate is preferably washed and dried before use to ensure that its surface is clean; the washing preferably includes washing with water, ethanol and acetone in sequence, and the washing is preferably carried out under ultrasonic conditions, specifically The substrate is placed in water, ethanol and acetone in sequence for ultrasonic cleaning; the drying is preferably blown dry with high-purity nitrogen.
  • the operation parameters for depositing BiOI on the surface of the substrate include: the temperature is preferably 20-30° C., specifically, the deposition is performed at room temperature; the deposition time is preferably 1-10 min, more preferably 4-6 min;
  • the working electrode is the FTO glass substrate, the counter electrode is preferably a platinum mesh electrode, and the reference electrode is preferably an Ag/AgCl electrode.
  • the present invention drips the vanadyl acetylacetonate solution onto the surface of the BiOI photoelectrode, and then performs calcination to obtain the BiVO 4 photoelectrode.
  • the solvent of the vanadyl acetylacetonate solution is preferably dimethyl sulfoxide (DMSO), and the concentration is preferably 0.1-5 mol/L, more preferably 0.2-2 mol/L, and the coating method is preferably For dispensing; in the laboratory solution of the present invention, the dispensing is preferably performed using a pipette.
  • the coating amount of the DMSO solution of vanadyl acetylacetonate on the surface of the BiOI photoelectrode is preferably 50-80 ⁇ L/cm 2 , more preferably 60-70 ⁇ L/cm 2 .
  • the temperature of the calcination is preferably 400-600°C, more preferably 450°C-500°C, and the time is preferably 1-6 hours, more preferably 2-3 hours, the present invention is preferably in a muffle furnace
  • the calcination is carried out.
  • the organic matter in the mixed solution can be removed, the bismuth source is converted into bismuth oxide, the vanadyl acetylacetonate is decomposed into vanadium oxide, and then the two undergo a high-temperature solid-phase reaction and are converted into bismuth vanadate to obtain BiVO 4 photoelectrode.
  • the obtained calcined product is preferably subjected to post-treatment, and the post-treatment is preferably as follows: the obtained calcined product is cooled and then soaked in alkaline solution, washed and dried.
  • the alkali solution is preferably a sodium hydroxide solution with a concentration of 1 mol/L; the soaking time of the alkali solution is preferably 20-60 minutes, more preferably 30-50 minutes.
  • the excess V 2 O 5 in the membrane electrode can be removed by soaking in the alkaline solution; the washing detergent is preferably deionized water, and the drying is preferably natural drying in the air.
  • the present invention places the BiVO 4 photoelectrode in a mixed electrolyte solution, uses the BiVO 4 photoelectrode as the working electrode, and uses a three-electrode system for cyclic voltammetry electrodeposition.
  • the parameters of the cyclic voltammetric electrodeposition preferably include: the scan rate is preferably 50-200mV/s, more preferably 75-180mV/s, more preferably 100-175mV/s, and most preferably 150mV/s s, the potential range is preferably -0.9 to 0V, and the number of cycles is preferably 3 to 100 times, more preferably 10 to 90 times, more preferably 20 to 80 times, and most preferably 50 times.
  • the present invention can limit the thickness of the prepared CoP promoter layer by limiting the concentration of each substance in the mixed electrolyte solution and the number of cycles of voltammetric electrodeposition, so that the obtained CoP promoter layer has better stability and water oxidation. catalytic effect.
  • the present invention performs cyclic voltammetric electrodeposition through a three-electrode system, electroreduces V 5+ on BiVO 4 to V 4+ , and at the same time introduces oxygen vacancies on the surface of BiVO 4 , Co 2+ and H 2 PO 2 in the solution - Converted to CoP and deposited on the outer layer of BiVO 4 , the hole transfer efficiency of BiVO 4 is improved by the introduction of oxygen vacancies and the loading of CoP, the reaction rate of water oxidation is increased, the activation energy of water oxidation is significantly reduced, and the photoelectrode of BiVO 4 is improved.
  • the carrier separation efficiency thereby inhibiting the recombination rate of photogenerated electrons and holes, realizes effective water splitting on the electrode surface under visible light driving conditions, directly makes photogenerated electrons gather on the photoelectrode FTO substrate, and drives photogenerated electrons to effectively transfer to
  • the protected metal achieves effective photocathode corrosion protection at open circuit potential, and the CoP layer deposited on the outer layer of BiVO 4 and the abundant oxygen vacancies can effectively improve the chemical resistance and photocorrosion resistance of the BiVO 4 layer under the synergistic effect, ensuring BiVO 4
  • the photoelectrode can be stably used in the anticorrosion of photogenerated cathodes.
  • the present invention also provides the BiVO 4 /CoP thin film electrode prepared by the preparation method described in the above scheme.
  • the BiVO 4 /CoP thin film electrode and the BiVO 4 /CoP thin film electrode include a BiVO 4 photoelectrode and a CoP assistant supported on the surface of the BiVO 4 photoelectrode . catalyst layer.
  • the thickness of the CoP promoter layer is preferably 2-50 nm.
  • the present invention limits the thickness of the CoP co-catalyst layer to 2-50 nm, which not only prevents the CoP co-catalyst layer from being too thin to catalyze water oxidation and reduces the activity of water oxidation, but also avoids that the CoP co-catalyst layer is too thick It affects the hole transport distance and avoids serious carrier recombination due to long transport distance, thereby weakening the water oxidation performance.
  • the present invention also provides the application of the BiVO 4 /CoP thin film electrode described in the above solution in the anticorrosion of photogenerated cathodes.
  • the cathode metal material in the application is preferably stainless steel, carbon steel, and titanium plate, and the stainless steel is preferably 304 stainless steel.
  • the method of application is preferably:
  • the BiVO 4 /CoP thin film electrode is placed in a photoanode cell, and the cathode metal material is placed in a corrosion cell; the photoanode cell and the corrosion cell are connected by a salt bridge;
  • the coupling electrodes are exposed to visible light irradiation.
  • the BiVO 4 /CoP thin film electrode provided by the present invention and its preparation method and application in the anticorrosion of photocathode are described in detail below with reference to the examples, but they should not be construed as limiting the protection scope of the present invention.
  • the concentration of sodium acetate in the CoP electrolyte is 3 mol/L, and the concentration of sodium hypophosphite is 0.15 mol/L , the concentration of cobalt acetate is 0.5mol/L;
  • the BiVO 4 film electrode is used as the working electrode, the platinum mesh electrode is used as the counter electrode, and the silver chloride electrode is used as the reference electrode. It is -0.9 ⁇ 0V, and the number of cycles is 40 times. Cyclic voltammetric electrodeposition is performed on the provided BiVO 4 thin film electrode to obtain a BiVO 4 /CoP thin film electrode.
  • the obtained BiVO 4 , BiVO 4 /CV and BiVO 4 /CoP thin film electrodes were subjected to X-ray diffraction test, and the obtained results are shown in FIG. 1 .
  • the diffraction peaks at 28.9 o , 30.5 o , 34.5 o , 35.1 o , 40.2 o and 42.4 o in the XRD spectrum are all monoclinic BiVO 4 (PDF#14-0688), corresponding to (121), (040), ( 200), (002), (112) and (051) planes.
  • the rest of the diffraction signal is attributed to SnO2 from the FTO substrate (PDF #46-1088).
  • the obtained BiVO 4 /CoP thin film electrode was detected by polar X-ray photoelectron spectroscopy, and the obtained results are shown in Figure 2 and Figure 3 , and Figure 2 is the Co element XPS of the BiVO 4 /CoP thin film electrode prepared in Example 1 3 is the P element XPS diagram of the BiVO 4 /CoP thin film electrode prepared in Example 1. It can be seen from Figure 2 and Figure 3 that there are two detection peaks at 781.7 and 804 eV in the X-ray photoelectron spectroscopy detection results of the BiVO 4 /CoP thin film electrode prepared in Example 1 of the present invention.
  • the above two detection peaks Corresponding to the Co 2p1/2 and Co 2p3/2 signals, respectively, the above two peaks can be deconvolved into Co 3+ and Co 2+ , respectively. And there is a detection peak at 132.5eV in the X-ray photoelectron spectroscopy detection result of the BiVO 4 /CoP thin film electrode prepared in Example 1 of the present invention, and the above detection peak corresponds to the P 2p signal, indicating that CoP was successfully loaded at BiVO 4 surface.
  • the surface roughness of the BiVO 4 /CoP thin film electrode prepared in Example 1 was detected, and it can be seen that the surface of the BiVO 4 /CoP thin film electrode prepared in Example 1 was rougher, and the rough structure layer was a small amount of CoP loading, indicating a small amount of CoP loading can improve the surface roughness of thin film electrodes.
  • the BiVO 4 photoelectrode was prepared according to the method of Example 1;
  • the obtained BiVO 4 /CoP thin film electrode was tested by scanning electron microscope, and the obtained results are shown in FIG. 4 . It can be seen from Fig. 4 that BiVO4 nanorods with an average diameter of about 200 ⁇ 70 nm are interconnected to form a nanopore network.
  • the SEM results of the BiVO 4 /CoP thin film electrode are basically consistent with the SEM test results of the BiVO 4 photoelectrode alone (Fig. 5). And the surface is relatively rough, indicating that a small amount of CoP is loaded on the surface of BiVO 4 .
  • the BiVO 4 photoelectrode was prepared according to the method of Example 1;
  • BiVO 4 /CV oxygen vacancy BiVO 4
  • the prepared BiVO 4 , BiVO 4 /CV and BiVO 4 /CoP thin film electrodes were characterized by Raman spectroscopy.
  • the characterization results are shown in Figure 6. It can be seen from the results that the Raman peaks at 325cm -1 and 368cm -1 are respectively
  • the Raman peaks at 708 cm -1 and 828 cm -1 belong to the asymmetric and symmetric bending vibrations of the VO 4 3- tetrahedron, which belong to the symmetric and antisymmetric stretching of the VO vibration.
  • the Raman signal is obviously weakened, and the Raman peak is red-shifted, which is caused by the generation of oxygen vacancies on the surface of BiVO 4 .
  • the BiVO 4 /CoP electrode has the lowest onset potential, indicating that oxygen holes and CoP can play a synergistic role to significantly reduce the activation energy of water oxidation, which is of great significance for improving the carrier separation efficiency of the BiVO 4 photoelectrode. It plays an important role in inhibiting the recombination of photogenerated electrons and holes, thereby increasing the lifetime of photogenerated electrons, and laying a good foundation for its application in photocathode anticorrosion.
  • the BiVO 4 photoelectrode was prepared according to the method of Example 1;
  • the sodium acetate concentration in the CoP electrolyte was 0.5 mol/L and the sodium hypophosphite concentration was 0.05 mol/L.
  • L the concentration of cobalt acetate is 0.02mol/L; the BiVO 4 film electrode is used as the working electrode, the platinum mesh electrode is used as the counter electrode, and the silver chloride electrode is used as the reference electrode.
  • the range is -0.9 ⁇ 0V, and the number of cycles is 20 times. Cyclic voltammetric electrodeposition is performed on the provided BiVO 4 thin film electrode to obtain the BiVO 4 /CoP thin film electrode.
  • BiVO 4 photoelectrode and BiVO 4 /CV thin film electrode were connected with 304 stainless steel according to the above method to prepare BiVO 4 -304 stainless steel coupling electrode and BiVO 4 /CV-304 stainless steel coupling electrode, as control group.
  • the BiVO 4 photoelectrode was prepared according to the method of Example 1;
  • the sodium acetate concentration in the CoP electrolyte was 1 mol/L, and the sodium hypophosphite concentration was 0.1 mol/L.
  • the concentration of cobalt acetate is 0.04mol/L;
  • the BiVO 4 film electrode is used as the working electrode, the platinum mesh electrode is used as the counter electrode, and the silver chloride electrode is used as the reference electrode.
  • the number of cycles is 10 times, and cyclic voltammetric electrodeposition is carried out on the provided BiVO 4 thin film electrode to obtain BiVO 4 /CoP thin film electrode.
  • BiVO 4 photoelectrode and BiVO 4 /CV thin film electrode were connected with 304 stainless steel according to the above method to prepare BiVO 4 -304 stainless steel coupling electrode and BiVO 4 /CV-304 stainless steel coupling electrode, as control group.
  • the Tafel polarization curves of BiVO 4 -304 stainless steel coupling electrode, BiVO 4 /CV-304 stainless steel coupling electrode and BiVO 4 /CoP-304 stainless steel coupling electrode were tested under visible light irradiation, and the results are shown in Figure 9. 9 shows the Tafel polarization curves of BiVO 4 -304 stainless steel coupling electrode, BiVO 4 /CV-304 stainless steel coupling electrode and BiVO 4 /CoP-304 stainless steel coupling electrode under visible light irradiation in Example 5.

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Abstract

本发明属于金属防腐技术领域，具体涉及一种BiVO 4/CoP薄膜电极及其制备方法和应用。本发明将乙酸盐、次亚磷酸盐、可溶性钴盐与溶剂混合，得到混合电解质溶液，并将BiVO 4光电极置于混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积，得到BiVO 4/CoP薄膜电极。实施例结果表明，本发明提供的BiVO 4/CoP薄膜电极载流子分离效率高，能够有效抑制光生电子-空穴的复合，提升光生电子的寿命，具有较好的光生阴极保护效果。

Description

一种BiVO 4/CoP薄膜电极及其制备方法和应用
本申请要求于2021年04月08日提交中国专利局、申请号为CN202110377321.3、发明名称为“一种BiVO 4/CoP薄膜电极及其制备方法和应用”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明属于金属防腐技术领域，具体涉及一种BiVO 4/CoP薄膜电极及其制备方法和应用。
背景技术
金属材料是人类历史上使用时间最长的材料之一。它们在工业、农业生产和科学研究领域中广泛用作结构材料和功能材料。然而，金属的热力学不稳定状态使其在使用过程中不可避免地具有腐蚀的趋势。金属腐蚀具有很大的破坏性。
目前，金属防腐技术可分为两类：物理屏障保护和电化学保护方法。物理屏障保护是通过在金属基板的表面上涂覆钝化层以防止氧气、水、盐的接触和渗透，从而防止金属与这些物质发生化学反应。电化学保护法则是通过外加电流使金属制品的电位发生变化，从而减缓或抑制金属制品的腐蚀。电化学保护分为两种，即阳极保护法和阴极保护法。其中，光电阴极保护是一种新型的阴极保护技术，不以防腐材料作为牺牲剂，无需消耗防腐材料，仅使用绿色清洁的太阳能来减缓甚至抑制金属材料的腐蚀，实现永久的保护。
光电阴极保护主要通过金属与光电极(由半导体材料制备得到)实现金属防腐，利用半导体涂层能在光照辐射条件下产生光生电子空穴对的效应，将半导体涂层受光激发产生的光生电子转移到基底金属材料上，从而实现对基底金属的保护。在光电阴极保护技术中，寻找更有效的半导体材料尤为重要。到目前为止，已经广泛开发了许多半导体，如TiO 2，SnO 2，α-Fe 2O 3/Fe 3O 4、BiVO 4等，它们可以提供足够的电子用于金属材料以减缓或防止氧化反应。
BiVO 4具有合适的带隙结构(Eg≈2.4eV)，可以在可见光驱动下驱动水氧化反应，还具有相对负的导带电位，热力学上有利于电子向保护金属的转移。但是，BiVO 4光电极的水氧化活性较差，电子空穴复合率较高，开路电位下光生电子难以从BiVO 4光电极转移至被保护金属上，从而限制了对金属的光生阴 极防护能力。此外，BiVO 4光电极稳定性较低，易发生化学腐蚀和光腐蚀，在光生阴极防腐中的应用并不稳定。
发明内容
本发明的目的在于提供一种BiVO 4/CoP薄膜电极及其制备方法和应用，本发明提供的BiVO 4/CoP薄膜电极水氧化活性好，耐化学腐蚀和光腐蚀的性能好，在光生阴极防腐中的应用时的稳定性好。
为了实现上述目的，本发明提供如下技术方案：
本发明提供了一种BiVO 4/CoP薄膜电极的制备方法，包括以下步骤：将乙酸盐、次亚磷酸盐、可溶性钴盐与溶剂混合，得到混合电解质溶液；
将BiVO 4光电极置于所述混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积，在所述BiVO 4光电极表面形成CoP助催化剂层，得到BiVO 4/CoP薄膜电极。
优选地，所述混合电解质溶液中乙酸盐的浓度为0.5～5mol/L，次亚磷酸盐的浓度为0.01～0.5mol/L，可溶性钴盐的浓度为0.02～1mol/L。
优选地，所述三电极系统的对电极为铂网电极，参比电极为氯化银电极。
优选地，所述循环伏安电沉积的条件包括：扫描速率为50～200mV/s，电位范围为-0.9～0V，循环次数为3～100次。
优选地，所述BiVO 4光电极包括基底和负载于所述基底表面的BiVO 4薄膜；所述BiVO 4薄膜的厚度为500～1000nm。
优选地，所述BiVO 4薄膜由BiVO 4纳米颗粒形成；所述BiVO 4纳米颗粒的粒度为100～200nm。
本发明还提供了上述制备方法制备得到的BiVO 4/CoP薄膜电极，所述BiVO 4/CoP薄膜电极包括BiVO 4光电极和负载于BiVO 4光电极表面的CoP助催化剂层。
优选地，所述CoP助催化剂层的厚度为2～50nm。
本发明还提供了上述方案所述BiVO 4/CoP薄膜电极在光生阴极防腐中的应用。
优选地，所述应用中的阴极金属材料为不锈钢、碳钢和钛板。
本发明提供了一种BiVO 4/CoP薄膜电极的制备方法，包括以下步骤：将乙酸钠、次亚磷酸钠、乙酸钴与溶剂混合，得到混合电解质溶；将BiVO 4光电极 置于混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积，得到BiVO 4/CoP薄膜电极。本发明通过循环伏安电沉积，将BiVO 4上的V 5+电还原为V 4+，进而在BiVO 4表面引入氧空位，同时，将溶液中的Co 2+和H 2PO 2－转换为CoP沉积于BiVO 4外层，通过氧空位的引入和CoP的负载改善BiVO 4的空穴转移效率，提高水氧化反应速率，显著降低了水氧化的活化能，提升了BiVO 4光电极的载流子分离效率，从而抑制了光生电子-空穴的复合速率，在可见光驱动条件下实现电极表面有效的水分解，直接使光生电子在光电极FTO基底上聚集，并驱动光生电子有效转移至被保护金属，实现了开路电位有效光电阴极防腐。沉积于BiVO 4外层的CoP层与丰富的氧空位在协同作用下能够有效提高BiVO 4层的耐化学腐蚀性和耐光腐蚀性，保证BiVO 4光电极能够稳定应用于光生阴极防腐中。
附图说明
图1为实施例1中所制备BiVO 4、BiVO 4/CV和BiVO 4/CoP薄膜电极的X射线衍射图；
图2为实施例1中所制备BiVO 4/CoP薄膜电极的Co元素XPS图；
图3为实施例1中所制备BiVO 4/CoP薄膜电极的P元素XPS图；
图4为实施例2中所制备BiVO 4/CoP薄膜电极的扫描电镜图；
图5为实施例2中所制备BiVO 4光电极的扫描电镜图；
图6为实施例3中所制备BiVO 4光电极、BiVO 4/CV薄膜电极和BiVO 4/CoP薄膜电极的拉曼光谱；
图7为实施例3中可见光照射下BiVO 4光电极、BiVO 4/CV薄膜电极和BiVO 4/CoP薄膜电极的光电流-时间曲线图；
图8为实施例4中BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极和BiVO 4/CoP-304不锈钢耦合电极在暗态和光照下的开路电位-时间曲线图；
图9为实施例5中可见光照射下BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极和BiVO 4/CoP-304不锈钢耦合电极的塔菲尔极化曲线。
具体实施方式
本发明提供了一种BiVO 4/CoP薄膜电极的制备方法，包括以下步骤：
将乙酸盐、次亚磷酸盐、可溶性钴盐与溶剂混合，得到混合电解质溶液；
将BiVO 4光电极置于混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积，在所述BiVO 4光电极表面形成CoP助催化剂层，得到BiVO 4/CoP薄膜电极。
本发明将乙酸盐、次亚磷酸盐、可溶性钴盐与溶剂混合，得到混合电解质溶液。在本发明中，所述乙酸盐优选包括乙酸钠、乙酸钾，进一步优选为乙酸钠，所述次亚磷酸盐优选包括次亚磷酸钠，所述可溶性钴盐优选包括乙酸钴，所述溶剂优选为水，进一步优选为超纯水；上述混合过程可采用本领域技术人员熟知的混合方式，例如：搅拌混合和超声混合等。在本发明中，所述混合电解质溶液中乙酸盐的浓度优选为0.5～5mol/L，进一步优选为1.5～4mol/L，更优选为2～3.5mol/L，最优选为3mol/L，次亚磷酸盐的浓度优选为0.01～0.5mol/L，进一步优选为0.05～0.4mol/L，更优选为0.1～0.3mol/L，最优选为0.2mol/L，可溶性钴盐的浓度优选为0.02～1mol/L，进一步优选为0.04～0.9mol/L，更优选为0.1～0.8mol/L，最优选为0.5mol/L。本发明将混合电解质溶液中各物质的浓度控制在上述范围，能够避免电解质溶液的浓度过高导致副反应程度增加，使制备得到的薄膜电极的杂质成分增加，同时避免了混合电解液溶液的浓度过低导致后续的循环伏安电沉积反应无法进行，最终无法得到BiVO 4/CoP薄膜电极。
得到混合电解质溶液后，本发明将BiVO 4光电极置于混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积，在BiVO 4光电极表面形成CoP助催化剂层，得到BiVO 4/CoP薄膜电极。
在本发明中，所述三电极系统以BiVO 4光电极为工作电极，对电极优选为铂网电极，参比电极优选为氯化银电极，本发明对所述氯化银电极、铂网电极的规格没有特殊的要求，使用本领域技术人员熟知的氯化银电极、铂网电极即可。
在本发明中，所述BiVO 4光电极包括基底和负载于所述基底表面的BiVO 4薄膜；所述BiVO 4薄膜的厚度优选为500～1000nm，所述基底优选为FTO玻璃基底；所述BiVO 4薄膜优选由BiVO 4纳米颗粒形成；所述BiVO 4纳米颗粒的粒度优选为100～200nm。
本发明对所述BiVO 4光电极的来源没有特殊限定，采用本领域技术人员熟知的方法制备得到即可；在本发明的具体实施例中，所述BiVO 4光电极的制备方法优选包括以下步骤：
(1)将可溶性铋源与KI溶液混合，得到铋源碘化钾混合液；
(2)将对苯醌与乙醇混合，得到对苯醌乙醇溶液；
(3)将所述铋源碘化钾混合液与对苯醌乙醇溶液混合进行超声处理，得到电解液；
(4)将基底置于所述电解液中，以所述基底为工作电极，采用三电极系统进行光电沉积，在基底表面形成BiOI膜，得到BiOI光电极；
(5)将乙酰丙酮氧钒溶液滴涂到BiOI光电极表面，之后进行煅烧，得到BiVO 4光电极。
本发明将可溶性铋源与KI溶液混合，得到铋源碘化钾混合液。在本发明中，所述可溶性铋源优选为硝酸铋；所述碘化钾溶液的浓度优选为0.1～1mol/L，更优选为0.2～0.6mol/L，所述碘化钾溶液的pH值优选为1～2，进一步优选为1.7。在本发明中，所述混合的方式优选为超声混合；所述超声混合的功率优选为200～600W，更优选为300～500W；时间优选为1～6h，更优选为2～4h；本发明通过所述超声混合，使可溶性铋源完全溶解在KI溶液中。在本发明中，所述铋源碘化钾混合液中的铋源的浓度优选为0.01～0.2mol/L，更优选为0.02～0.1mol/L。
本发明将对苯醌与乙醇混合，得到对苯醌乙醇溶液。在本发明中，所述对苯醌乙醇溶液中的对苯醌的浓度优选为0.1～1mol/L，更优选为0.2～0.6mol/L。在本发明中，所述混合的方式优选为超声混合；所述超声混合的功率优选为200～600W，更优选为300～500W；时间优选为0.5～3h，更优选为0.5～1h；本发明通过所述超声混合，使对苯醌完全溶解在乙醇中。
得到铋源碘化钾混合液和对苯醌乙醇溶液后，本发明将所述铋源碘化钾混合液和对苯醌乙醇溶液混合超声处理，得到电解质溶液。所述超声处理的功率优选为200～600W，更优选为300～500W，所述超声处理的时间优选为20min。
得到电解液后，本发明将基底置于所述电解液中，以所述基底为工作电极，采用三电极系统进行光电沉积，在基底表面形成BiOI膜，得到BiOI光电极。在本发明中，所述基底在使用前优选进行洗涤和干燥，以保证其表面洁净；所述洗涤优选包括依次进行的水洗、乙醇洗和丙酮洗，所述洗涤优选在超声条件下进行，具体是将基底依次置于水、乙醇和丙酮中进行超声清洗；所述干燥优选为采用高纯氮气吹干。
本发明中，在所述基底的表面沉积BiOI的操作参数包括：温度优选为20～30℃，具体是在室温条件下进行沉积；沉积时间优选为1～10min，更优选为4～6min；所述三电极系统中工作电极为所述FTO玻璃基底，对电极优选为铂网电极，参比电极优选为Ag/AgCl电极。
得到沉积有BiOI膜的基底后，本发明将乙酰丙酮氧钒溶液滴涂到BiOI光电极表面，之后进行煅烧，得到BiVO 4光电极。在本发明中，所述乙酰丙酮氧钒溶液的溶剂优选为二甲基亚砜(DMSO)，浓度优选为0.1～5mol/L，更优选为0.2～2mol/L，所述涂覆的方式优选为滴涂；本发明的实验室方案中，优选使用移液枪进行所述滴涂。在本发明中，所述乙酰丙酮氧钒的DMSO溶液涂覆在BiOI光电极表面的涂覆量优选为50～80μL/cm 2，更优选为60～70μL/cm 2。
在本发明中，所述煅烧的温度优选为400～600℃，更优选为450℃～500℃，时间优选为1～6小时，更优选为2～3小时，本发明优选在马弗炉中进行所述煅烧。本发明通过所述煅烧，能够除去混合液中的有机物，同时使铋源转化为氧化铋，乙酰丙酮氧钒分解为氧化钒，然后两者发生高温固相反应转化为钒酸铋，得到BiVO 4光电极。
煅烧完成后，本发明优选将所得煅烧产物进行后处理，所述后处理优选为：将所得煅烧产物降温后进行碱液浸泡、洗涤和干燥。在本发明中，所述碱液优选为浓度为1mol/L的氢氧化钠溶液；所述碱液浸泡的时间优选为20～60min，更优选为30～50min。本发明通过所述碱液浸泡，能够去除薄膜电极中过剩的V 2O 5；所述洗涤用洗涤剂优选为去离子水，所述干燥优选为在空气中自然晾干。
得到上述BiVO 4光电极后，本发明将BiVO 4光电极置于混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积。在本发明中，所述循环伏安电沉积的参数优选包括：扫描速率优选为50～200mV/s，进一步优选为75～180mV/s，更优选为100～175mV/s，最优选为150mV/s，所述电位范围优选为-0.9～0V，所述循环次数优选为3～100次，进一步优选为10～90次，更优选为20～80次，最优选为50次。
本发明通过对混合电解质溶液中各物质的浓度以及伏安电沉积的循环次数进行限定，能够限定制备得到的CoP助催化剂层的厚度，使所得CoP助催化剂层具有较好的稳定性和水氧化催化效果。
本发明通过三电极系统进行循环伏安电沉积，将BiVO 4上的V 5+电还原为 V 4+，在BiVO 4表面引入氧空位的同时，将溶液中的Co 2+和H 2PO 2－转换为CoP沉积于BiVO 4外层，通过氧空位的引入和CoP的负载改善BiVO 4的空穴转移效率，提高水氧化反应速率，显著降低了水氧化的活化能，提升BiVO 4光电极的载流子分离效率，从而抑制了光生电子-空穴的复合速率，在可见光驱动条件下实现电极表面有效的水分解，直接使光生电子在光电极FTO基底上聚集，并驱动光生电子有效转移至被保护金属，实现了开路电位有效光电阴极防腐，并且沉积于BiVO 4外层的CoP层与丰富的氧空位在协同作用下能够有效提高BiVO 4层的耐化学腐蚀性和耐光腐蚀性，保证BiVO 4光电极能够稳定应用于光生阴极防腐中。
本发明还提供了上述方案所述制备方法制备的BiVO 4/CoP薄膜电极，所述BiVO 4/CoP薄膜电极BiVO 4/CoP薄膜电极包括BiVO 4光电极和负载于BiVO 4光电极表面的CoP助催化剂层。
在本发明中，所述CoP助催化剂层的厚度优选为2～50nm。本发明限定CoP助催化剂层的厚度为2～50nm，不仅避免了CoP助催化剂层过薄无法起到催化水氧化的作用，降低水氧化的活性的效果，同时也避免了CoP助催化剂层过厚影响空穴传输距离，避免因传输距离长而导致载流子复合严重，进而削弱水氧化性能。
本发明还提供了上述方案所述BiVO 4/CoP薄膜电极在光生阴极防腐中的应用，在本发明中，所述应用中的阴极金属材料优选为不锈钢、碳钢、钛板，所述不锈钢优选为304不锈钢。
在本发明中，所述应用的方法优选为：
将所述BiVO 4/CoP薄膜电极置于光阳极池内，将所述阴极金属材料置于腐蚀池内；所述光阳极池和腐蚀池通过盐桥相接；
将BiVO 4/CoP薄膜电极与阴极金属材料通过导线连接，得到耦合电极；
将所述耦合电极置于可见光照射条件下。
在本发明中，所述光阳极池中的电解质优选为pH＝9的KHCO 3溶液；所述腐蚀池中的电解质优选为3.5wt％的NaCl溶液。
下面结合实施例对本发明提供的BiVO 4/CoP薄膜电极及其制备方法和在光生阴极防腐中的应用进行详细的说明，但是不能把它们理解为对本发明保护范围的限定。
实施例1
将碘化钾和超纯水混合，采用浓硝酸(浓度为68wt％)调节pH值为1.7，得到浓度为0.4mol/L的碘化钾水溶液；将硝酸铋与所述碘化钾水溶液混合，超声溶解，得到碘化钾-硝酸铋混合液，所述碘化钾-硝酸铋混合液中硝酸铋的浓度为0.04mol/L；
将对苯醌与乙醇混合，超声溶解，得到对苯醌溶液，所述对苯醌溶液中对苯醌的浓度为0.2mol/L；
将所述碘化钾-硝酸铋混合液和对苯醌溶液混合，搅拌均匀，以混合后的溶液为电解质溶液，采用FTO导电玻璃为工作电极，Ag/AgCl电极为参比电极，铂网为对电极，在电位为-0.1V的条件下电沉积5min，沉积结束后利用去离子水清洗去除表面杂质，得到BiOI光电极；
将乙酰丙酮钒与二甲基亚砜混合，得到浓度为0.2mol/L的乙酰丙酮氧钒溶液，用移液枪移取65μL所述乙酰丙酮氧钒溶液滴涂在所述BiOI电极表面(乙酰丙酮氧钒溶液的滴涂量为65μL/cm 2)，之后于马弗炉中450℃条件下煅烧2h，自然冷却至室温后取出所得光电极置于1mol/L的氢氧化钠溶液中，在室温(25℃)条件下浸泡30min，以去除残余的V 2O 5，得到BiVO 4光电极；
在pH＝6.6的乙酸钠溶液中加入次亚磷酸钠和乙酸钴，经搅拌溶解得到CoP电解液，所述CoP电解液中乙酸钠浓度为3mol/L，次亚磷酸钠浓度为0.15mol/L，乙酸钴浓度为0.5mol/L；以BiVO 4薄膜电极为工作电极，铂网电极为对电极，氯化银电极为参比电极，利用三电极系统，设置扫描速率为150mV/s，电位范围为-0.9～0V，循环次数为40次，在提供的BiVO 4薄膜电极上进行循环伏安电沉积，得到BiVO 4/CoP薄膜电极。
作为对比，以pH＝6.6的乙酸钠溶液为电解液，乙酸钠浓度为1.5mol/L，不添加次亚磷酸钠和乙酸钴；在相同操作参数下利用三电极系统进行循环伏安电沉积，BiVO 4上的V 5+电还原为V 4+，进而BiVO 4表面引入氧空位，制备得到氧空位型BiVO 4，记为BiVO 4/CV。
将所得BiVO 4、BiVO 4/CV和BiVO 4/CoP薄膜电极进行X射线衍射测试，所得结果如图1所示。XRD谱图中28.9 o、30.5 o、34.5 o、35.1 o、40.2 o和42.4 o的衍射峰均为单斜BiVO 4(PDF#14-0688)，分别对应于(121)、(040)、(200)、(002)、(112)和(051)的晶面。其余的衍射信号归因于来自FTO衬底的SnO 2(PDF #46-1088)。通过XRD可以证实合成的BiVO 4是纯相的，不含有其他杂质相。但是，通过XRD并未观察到CoP，说明循环伏安法获得的CoP为非晶，或者是CoP含量太低，导致未探测到。
将所得BiVO 4/CoP薄膜电极极性X-射线光电子能谱探测，所得结果如图2和图3所示，所述图2为实施例1中所制备BiVO 4/CoP薄膜电极的Co元素XPS图，所述图3为实施例1中所制备BiVO 4/CoP薄膜电极的P元素XPS图。由图2和图3可以看出，本发明实施例1所制备的BiVO 4/CoP薄膜电极的X-射线光电子能谱探测结果中于781.7和804eV处有两个探测峰，上述两个探测峰分别对应于Co 2p1/2和Co 2p3/2信号，上述两个峰分别可以反卷积成Co 3+和Co 2+。并且本发明实施例1所制备的BiVO 4/CoP薄膜电极的X-射线光电子能谱探测结果中在132.5eV处有一个探测峰，上述探测峰对应于P 2p信号，说明CoP被成功的负载在BiVO 4表面。对实施例1所制备BiVO 4/CoP薄膜电极表面粗糙程度进行检测，可以看出实施例1所制备的BiVO 4/CoP薄膜电极表面更粗糙，该粗糙结构层即为少量的CoP负载，说明少量CoP负载后能够提高薄膜电极的表面粗糙度。
实施例2
按照实施例1的方法制备得到BiVO 4光电极；
在pH＝6.6的乙酸钠溶液中加入次亚磷酸钠和乙酸钴，经搅拌溶解得到CoP电解液，所述CoP电解液中乙酸钠浓度为2mol/L，次亚磷酸钠浓度为0.2mol/L，乙酸钴浓度为0.1mol/L；以BiVO 4薄膜电极为工作电极，铂网电极为对电极，氯化银电极为参比电极，利用三电极系统，设置扫描速率为100mV/s，电位范围为-0.9～0V，循环次数为20次，在提供的BiVO 4薄膜电极上进行循环伏安电沉积，得到BiVO 4/CoP薄膜电极。
将所得BiVO 4/CoP薄膜电极进行扫描电镜测试，所得结果如图4所示。由图4可以看出，平均直径约为200±70nm的BiVO 4纳米棒相互连接，形成纳米孔网络。而BiVO 4/CoP薄膜电极的扫描电镜结果与单独的BiVO 4光电极扫描电镜测试结果图5基本一致。并且表面较为粗糙，说明有少量CoP负载在BiVO 4表面。
实施例3
按照实施例1的方法制备得到BiVO 4光电极；
在pH＝6.6的乙酸钠溶液中加入次亚磷酸钠和乙酸钴，经搅拌溶解得到CoP电解液，所述CoP电解液中乙酸钠浓度为1.5mol/L，次亚磷酸钠浓度为0.1mol/L，乙酸钴浓度为0.2mol/L；以BiVO 4薄膜电极为工作电极，铂网电极为对电极，氯化银电极为参比电极，利用三电极系统，设置扫描速率为75mV/s，电位范围为-0.9～0V，循环次数为50次，在提供的BiVO 4薄膜电极上进行循环伏安电沉积，得到BiVO 4/CoP薄膜电极。
作为对比，以pH＝6.6的乙酸钠溶液为电解液，乙酸钠浓度为1.5mol/L，不添加次亚磷酸钠和乙酸钴；在相同操作参数下利用三电极系统进行循环伏安电沉积，BiVO 4上的V 5+电还原为V 4+，进而BiVO 4表面引入氧空位，制备得到氧空位型BiVO 4(简写为BiVO 4/CV)。
采用拉曼光谱对所制备的BiVO 4、BiVO 4/CV和BiVO 4/CoP薄膜电极进行表征，表征结果如图6所示，由结果可知，位于325cm -1和368cm -1的拉曼峰分别属于VO 4 3-四面体的非对称和对称弯曲振动，708cm -1和828cm -1的拉曼峰属于V-O振动的对称和反对称伸缩。对于BiVO 4/CV薄膜而言，拉曼信号明显减弱，且拉曼峰位发生红移，这是BiVO 4表面产生氧空位所导致的。此外，对于BiVO 4/CoP薄膜电极，其拉曼信号强度也交单独的BiVO 4要低，说明氧空位的产生降低了材料的结晶性。但是，相比于BiVO 4/CV样品，BiVO 4/CoP的峰位红移较少，说明CoP负载以后改变了材料的拉曼散射。
在可见光照射下分别测试BiVO 4/CoP薄膜电极、BiVO 4/CV薄膜电极和BiVO 4光电极的光电流，所得结果如图7所示。由图7可以看出，BiVO 4/CoP和BiVO 4/CV的光电流比单纯的BiVO 4要大，说明氧空位的引入和CoP的负载确实可以改善BiVO 4的空穴转移效率，进而提高水氧化反应速率。此外，还可以注意到BiVO 4/CoP电极的起始电位最低，说明氧空穴和CoP可以发挥协同作用，显著降低水氧化的活化能，这对于提升BiVO 4光电极的载流子分离效率具有重要的作用，有利于抑制光生电子-空穴的复合，进而提升光生电子的寿命，为其在光电阴极防腐中的应用奠定良好的基础。
实施例4
按照实施例1的方法制备得到BiVO 4光电极；
在pH＝6.6的乙酸钠溶液中加入次亚磷酸钠和乙酸钴，经搅拌溶解得到CoP电解液，所述CoP电解液中乙酸钠浓度为0.5mol/L，次亚磷酸钠浓度为 0.05mol/L，乙酸钴浓度为0.02mol/L；以BiVO 4薄膜电极为工作电极，铂网电极为对电极，氯化银电极为参比电极，利用三电极系统，设置扫描速率为75mV/s，电位范围为-0.9～0V，循环次数为20次，在提供的BiVO 4薄膜电极上进行循环伏安电沉积，得到BiVO 4/CoP薄膜电极。
以pH＝6.6的乙酸钠溶液为电解液，乙酸钠浓度为0.5mol/L，不添加次亚磷酸钠和乙酸钴；在相同操作参数下利用三电极系统进行循环伏安电沉积得到BiVO 4/CV薄膜电极。
将所得的BiVO 4/CoP薄膜电极通过铜线与304不锈钢连接，制备BiVO 4/CoP-304不锈钢耦合电极，其中BiVO 4/CoP薄膜电极置于光阳极池内，光阳极池中的电解质为pH＝9的KHCO 3溶液；304不锈钢置于腐蚀池中，腐蚀池中的电解质为3.5wt％的NaCl溶液；所述光阳极池和腐蚀池通过盐桥相接。
使用BiVO 4光电极和BiVO 4/CV薄膜电极按照上述方法与304不锈钢连接制备BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极，作为对照组。
BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极和BiVO 4/CoP-304不锈钢耦合电极在暗态和光照下的开路电位-时间曲线图如图8所示，所述图8为实施例4中BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极和BiVO 4/CoP-304不锈钢耦合电极在暗态和光照下的开路电位-时间曲线图。由图8可以看出，光照后，三种耦合电极的开路电位均分别负移至-0.26、-0.3、-0.42V处，这说明光照后，半导体电极上产生的光生电子可以转移至304不锈钢上，从而导致开路电位负向移动。光照下的开路电位越负，光生电子聚集越多，转移至被保护金属上的电子也越多，保护能力也越强，可以看出，经过循环伏安处理后的BiVO 4光电极拥有对304不锈钢更好的防腐蚀作用。
实施例5
按照实施例1的方法制备得到BiVO 4光电极；
在pH＝6.6的乙酸钠溶液中加入次亚磷酸钠和乙酸钴，经搅拌溶解得到CoP电解液，所述CoP电解液中乙酸钠浓度为1mol/L，次亚磷酸钠浓度为0.1mol/L，乙酸钴浓度为0.04mol/L；以BiVO 4薄膜电极为工作电极，铂网电极为对电极，氯化银电极为参比电极，利用三电极系统，设置扫描速率为50mV/s，电位范围为-0.9～0V，循环次数为10次，在提供的BiVO 4薄膜电极上进行循环伏安电沉 积，得到BiVO 4/CoP薄膜电极。
以pH＝6.6的乙酸钠溶液为电解液，乙酸钠浓度为1mol/L，不添加次亚磷酸钠和乙酸钴；在相同操作参数下利用三电极系统进行循环伏安电沉积得到BiVO 4/CV薄膜电极。
将所得的BiVO 4/CoP薄膜电极通过铜线与304不锈钢连接，制备BiVO 4/CoP-304不锈钢耦合电极，其中BiVO 4/CoP薄膜电极置于光阳极池内，光阳极池中的电解质为pH＝9的KHCO 3溶液；304不锈钢置于腐蚀池中，腐蚀池中的电解质为3.5wt％的NaCl溶液；所述光阳极池和腐蚀池通过盐桥相接。
使用BiVO 4光电极和BiVO 4/CV薄膜电极按照上述方法与304不锈钢连接制备BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极，作为对照组。在可见光照射下分别测试BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极和BiVO 4/CoP-304不锈钢耦合电极的塔菲尔极化曲线，所得结果如图9所示，所述图9为实施例5中可见光照射下BiVO 4-304不锈钢耦合电极、BiVO 4/CV-304不锈钢耦合电极和BiVO 4/CoP-304不锈钢耦合电极的塔菲尔极化曲线。由图9可以看出，在可见光光照下，三种耦合体系的自腐蚀电位分别为-0.32V、-0.34V、-0.44V。不锈钢上电子浓度越高，自腐蚀电位越负，光生阴极保护效果越好。可以看出，循环伏安处理后的BiVO 4的防腐效果明显增强，这也说明光照下改性电极上的光生电子能够更好的转移至304不锈钢上，进而避免其遭受腐蚀。
尽管上述实施例对本发明做出了详尽的描述，但它仅仅是本发明一部分实施例，而不是全部实施例，人们还可以根据本实施例在不经创造性前提下获得其他实施例，这些实施例都属于本发明保护范围。

Claims (13)

  1. 一种BiVO 4/CoP薄膜电极的制备方法，其特征在于，包括以下步骤：
    将乙酸盐、次亚磷酸盐、可溶性钴盐与溶剂混合，得到混合电解质溶液；
    将BiVO 4光电极置于所述混合电解质溶液中，以BiVO 4光电极为工作电极，采用三电极系统进行循环伏安电沉积，在所述BiVO 4光电极表面形成CoP助催化剂层，得到BiVO 4/CoP薄膜电极。
  2. 根据权利要求1所述的制备方法，其特征在于，所述混合电解质溶液中乙酸盐的浓度为0.5～5mol/L，次亚磷酸盐的浓度为0.01～0.5mol/L，可溶性钴盐的浓度为0.02～1mol/L。
  3. 根据权利要求1或2所述的制备方法，其特征在于，所述乙酸盐包括乙酸钠或乙酸钾；
    所述次亚磷酸盐包括次亚磷酸钠；
    所述可溶性钴盐包括乙酸钴。
  4. 根据权利要求1所述的制备方法，其特征在于，所述三电极系统的对电极为铂网电极，参比电极为氯化银电极。
  5. 根据权利要求1或4所述的制备方法，其特征在于，所述循环伏安电沉积的条件包括：扫描速率为50～200mV/s，电位范围为-0.9～0V，循环次数为3～100次。
  6. 根据权利要求1所述的制备方法，其特征在于，所述BiVO 4光电极包括基底和负载于所述基底表面的BiVO 4薄膜；所述BiVO 4薄膜的厚度为500～1000nm。
  7. 根据权利要求5所述的制备方法，其特征在于，所述BiVO 4薄膜由BiVO 4纳米颗粒形成；所述BiVO 4纳米颗粒的粒度为100～200nm。
  8. 权利要求1～7任一项所述制备方法制备的BiVO 4/CoP薄膜电极，其特征在于，所述BiVO 4/CoP薄膜电极包括BiVO 4光电极和负载于BiVO 4光电极表面的CoP助催化剂层。
  9. 根据权利要求8所述的BiVO 4/CoP薄膜电极，其特征在于，所述CoP助催化剂层的厚度为2～50nm。
  10. 权利要求8或9所述的BiVO 4/CoP薄膜电极在光生阴极防腐中的应用。
  11. 根据权利要求10所述的应用，其特征在于，所述应用的方法包括以下步骤：
    将所述BiVO 4/CoP薄膜电极置于光阳极池内，将所述阴极金属材料置于腐蚀池内；所述光阳极池和腐蚀池通过盐桥相接；
    将BiVO 4/CoP薄膜电极与阴极金属材料通过导线连接，得到耦合电极。
  12. 根据权利要求11所述的应用，其特征在于，所述阴极金属材料为不锈钢、碳钢和钛板。
  13. 根据权利要求11所述的应用，其特征在于，所述光阳极池中的电解质为pH＝9的KHCO 3溶液；所述腐蚀池中的电解质为3.5wt％的NaCl溶液。
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Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109569630A (zh) * 2019-01-23 2019-04-05 西北师范大学 一种负载镍钴水滑石纳米粒子的钒酸铋复合材料制备及在光电水氧化中的应用

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
BAI, HONGYE ET AL.: "Reasonable regulation of kinetics over BiVO4 photoanode by Fe-CoP catalysts for boosting photoelectrochemical water splitting", INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 44, 27 September 2019 (2019-09-27), XP085861243, ISSN: 0360-3199, DOI: 10.1016/j.ijhydene.2019.09.024 *
LI HAILI: "Enhanced the Photoelectrocatalytic Activities of BiVO4and α-Fe2O3and Photoelectrochemical Protection of Cu", MASTER THESIS, TIANJIN POLYTECHNIC UNIVERSITY, CN, no. 6, 15 June 2014 (2014-06-15), CN , XP055976455, ISSN: 1674-0246 *
LI TING-TING, ZHOU QIANQIAN, QIAN JINJIE, HU YUE, ZHENG YUE-QING: "Electrodeposition of a cobalt phosphide film for the enhanced photoelectrochemical water oxidation with α-Fe2O3 photoanode", ELECTROCHIMICA ACTA, ELSEVIER, AMSTERDAM, NL, vol. 307, 1 June 2019 (2019-06-01), AMSTERDAM, NL , pages 92 - 99, XP055976452, ISSN: 0013-4686, DOI: 10.1016/j.electacta.2019.03.183 *

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