CN103474517A - Preparation method of SrTiO3 nanocomposite film photoanode - Google Patents

Abstract

The invention discloses a preparation method of a SrTiO ₃ nanocomposite film photoanode, relating to a photoanode. Provided is a method for preparing a SrTiO ₃ nanocomposite film photoanode with high-efficiency photogenerated cathodic protection effect. 1) Preparation of titanium substrate: use titanium foil as the substrate, and obtain titanium substrate after ultrasonic treatment; 2) Preparation of TiO ₂ nanotube array film: use titanium substrate as anode and platinum sheet as cathode, perform anodic oxidation reaction, wash and dry , calcined to get TiO ₂ nanotube array film on titanium substrate; 3) Preparation of SrTiO ₃ nanocomposite film photoanode: put the titanium substrate covered with TiO ₂ nanotube array film prepared in step 2) into PTFE Add Sr(OH) ₂ solution to ethylene reactor, after reaction, soak in HCl solution, wash, dry, and calcinate to get SrTiO ₃ nanocomposite film photoanode, which is SrTiO ₃ /TiO with PN heterostructure ₂ composite materials.

Description

Preparation method of SrTiO3 nanocomposite film photoanode

technical field

The invention relates to a photoanode, in particular to a preparation method of a _SrTiO3 nanocomposite film photoanode with good photogenerated cathodic protection performance.

Background technique

The development and prosperity of the world economy benefit from non-renewable fossil resources. However, fossil resources are rapidly approaching depletion, and their use produces serious environmental pollution. Facing the double pressure of economic development and environmental protection, the development of renewable energy is a difficult problem that human beings must solve. Solar energy is an inexhaustible and inexhaustible renewable energy source, and more importantly, it does not produce environmental pollution during use. Photoelectric conversion is an important aspect of solar energy utilization. It is mainly based on semiconductor materials and uses light to generate electron-hole pairs, thereby generating photocurrent and photovoltage phenomena.

_TiO2 is an important multifunctional inorganic semiconductor material, which has broad application prospects in the fields of gas sensors, pollutant degradation, solar hydrogen production and solar cells. Compared with nanoparticles, one-dimensional nanomaterials have larger specific surface area, unique optical and electrical properties, and facilitate electron transport. Therefore, the development of TiO ₂ one-dimensional nanomaterials, especially the preparation of special nanostructure materials such as ordered arrays constructed by TiO 2 , is of great value in improving its performance and promoting its application. Anodic oxidation is a simple and effective method to prepare TiO ₂ nanotube array film on the surface of titanium substrate. The _TiO2 nanotube array film prepared by this method is directly formed on the surface of the titanium substrate, and has the advantages of vertical orientation and regular arrangement. However, the defects of TiO ₂ material itself limit its application in solar energy conversion. First, TiO ₂ has a wide band gap (3.0-3.2eV), which can only absorb ultraviolet light, and the utilization rate of solar energy is only 3%-4%. . The second is the rapid recombination of photogenerated electron-hole pairs. In view of the above problems, researchers often use methods such as ion doping, surface modification and noble metal deposition to modify TiO ₂ materials. Among them, coupling a semiconductor species with a different energy level from _TiO2 is considered to be an effective way to suppress the recombination of photogenerated electron-hole pairs.

In recent years, the role of heterostructures in photoelectric conversion has been paid more and more attention by researchers. The reported heterostructures such as ZnO-TiO ₂ , CdS-TiO ₂ , Cu ₂ O-TiO ₂ can effectively improve the current carrying capacity. child separation. SrTiO ₃ is a typical cubic perovskite structure and a P-type semiconductor. It is widely used in optoelectronic devices, photocatalysts, microcapacitors and ferroelectric memories because of its resistance to light corrosion and chemical corrosion and stable performance (Kurokawa H, Yang L M et al .,Y-doped SrTiO ₃ based sulfurtolerant anode for solid oxide fuel cells[J].Journal of Power Sources,2007,164:510-518;Sun T,Lu M,Modification of SrTiO ₃ surface by nitrogen ion bombardment for enhanced photocatalysis [J].Applied Surface Science,2013,274:176-180; Hu Z Q,Li Q et al.,Ferroelectric memristor based on Pt/BiFeO ₃ /Nb-doped SrTiO3 heterostructure[J].Applied Physics Letters,2013,102: 102901. The band gap of SrTiO ₃ (Eg=3.2eV) is similar to that of TiO ₂ , but its conduction band potential is negative (Subramanian V, Roeder R K et al., Synthesis and UV-visible-light photoactivity of noble-metal-SrTiO ₃ composites [J].Industrial & Engineering Chemistry Research,2006,45:2187-2193), the combination of the two can form a potential barrier at the interface, change the migration process of photogenerated carriers, and finally promote the effective separation of photogenerated electron-hole pairs, To achieve the purpose of improving photoelectric conversion.

Contents of the invention

The purpose of the present invention is to overcome the problems of fast recombination speed of photogenerated carriers and low photoelectric conversion efficiency of a single _TiO2 nanomaterial, and provide a method for preparing a _SrTiO3 nanocomposite film photoanode with high-efficiency photogenerated cathodic protection effect.

The present invention comprises the following steps:

1) Preparation of titanium substrate: use titanium foil as a substrate, and obtain a titanium substrate after ultrasonication;

2) Preparation of TiO ₂ nanotube array film: use titanium substrate as anode and platinum sheet as cathode, after anodic oxidation reaction, wash, dry, and calcinate to obtain TiO ₂ nanotube array film on titanium substrate;

3) Preparation of SrTiO ₃ nanocomposite film photoanode: Put the titanium substrate covered with TiO ₂ nanotube array film prepared in step 2) into a polytetrafluoroethylene reactor, add Sr(OH) ₂ solution, after the reaction , soaked in HCl solution, washed, dried, and calcined to obtain a SrTiO ₃ nanocomposite film photoanode, which is a SrTiO ₃ /TiO ₂ composite material with a PN heterostructure.

In step 1), the thickness of the titanium foil can be 0.05-0.15mm, the length can be 1.0-2.0cm, the width can be 0.5-1.5cm, and the purity of the titanium foil is preferably >99.7%; the ultrasonic can be sequentially Sonicate in acetone, absolute ethanol and deionized water, and the time of sonication can be 25-40min.

In step 2), the conditions of the anodic oxidation reaction can be: the electrolyte solution used for the anodic oxidation reaction contains NH ₄ F (0.45-0.55) wt%, and the ratio of glycerol to water is 3: (1-3 ), the voltage of the anodic oxidation reaction is 15-25V, and the time of the anodic oxidation reaction is 0.5-1.5h; the cleaning can be cleaned with deionized water; the calcination can be calcined in a muffle furnace, and the calcination temperature is 420- 470°C, the calcination time is 100-150min.

In step 3), the added amount of the Sr(OH) ₂ solution may be 35-45mL, and the concentration of the Sr(OH) ₂ solution may be 0.005-0.015M; the reaction temperature may be 160-200°C, The reaction time can be 20-80min; the concentration of the HCl solution can be 0.005-0.015M, the soaking time can be 0.5-1.5min; the cleaning can be cleaned with deionized water; It is calcined in a furnace, the calcining temperature is 420-470°C, and the calcining time is 100-150min.

SrTiO ₃ nanocomposite film photoanode photogenerated cathodic protection effect test can adopt the following method: use a double electrolytic cell system composed of a photoelectrolytic cell and a corrosion electrolytic cell, the SrTiO ₃ composite film is a photoanode, placed in a photoelectrolytic cell, and the electrolyte is ( 0.05～0.15)M NaOH+(0.05～0.15)M NaCOOH solution. The corrosion electrolytic cell is a three-electrode system, the working electrode is a protected metal (stainless steel, etc.), the reference electrode is a saturated calomel electrode, the counter electrode is a Pt electrode, and (0.3-0.8) M NaCl solution is used as the corrosion medium. The photoanode and the protected metal electrode are connected by a wire, and the photoelectrolyte and the corrosion electrolytic cell are connected by a salt bridge (agar containing 1.0mol/L KCl). When illuminating, a 150W high-pressure Xe lamp is used as a white light source, and is directly irradiated on the surface of the photoanode in the photoelectrolytic cell.

The present invention prepares TiO ₂ nanotube array film on the surface of titanium foil by electrochemical anodic oxidation method, adopts hydrothermal method to make TiO ₂ on the surface of nanotube react to generate SrTiO ₃ nanoparticles, and prepares SrTiO ₃ /TiO ₂ Composite film. The prepared composite film was used as a photoanode and connected to the metal in the corrosive medium to test its photogenerated cathodic protection performance.

In the present invention, TiO ₂ nanotube arrays are prepared on the surface of titanium foil substrate by electrochemical anodic oxidation, and then the TiO ₂ on the tube surface is converted into SrTiO ₃ nanoparticles by hydrothermal method, so as to obtain a novel SrTiO ₃ / _TiO2 composites. Under white light irradiation, this composite material can be used as a photoanode to obtain effective photogenerated cathodic protection for connected metal materials such as stainless steel, and its performance is significantly better than that of pure _TiO2 photoanode.

The basic principle of the present invention is: when the light energy is high enough, SrTiO ₃ and TiO ₂ undergo interband transition at the same time, because the conduction band position of SrTiO ₃ is at a relatively negative potential, the photogenerated electrons generated by the excitation of SrTiO ₃ are transferred to TiO ₂ . The surface enrichment of TiO ₂ correspondingly reduces the electron density on the surface of SrTiO ₃ . At the same time, TiO ₂ is excited to generate electron-hole pairs, and the holes migrate to the valence band of SrTiO ₃ with lower energy, which means that the photogenerated electrons and holes generated by the excited SrTiO ₃ /TiO ₂ heterojunction react rapidly To move, thereby reducing the recombination of photogenerated electrons and holes. On the other hand, TiO ₂ is an N-type semiconductor, and SrTiO ₃ is a P-type semiconductor. When the two are in contact, an internal electric field will be generated near the interface, and its direction is from N to P, which accelerates the movement of electrons and holes, which can further The recombination probability of electrons and holes is reduced.

The present invention has successfully prepared the SrTiO ₃ nanocomposite film with PN heterostructure composed of SrTiO ₃ and TiO ₂ , which has the characteristics of uniform and complete coating, can be used as a photoanode, and can protect the connected ones in photogenerated cathodic protection The electrode potential of the metal drops significantly, and more importantly, it can maintain excellent cathodic protection for a long time in the dark state. The _SrTiO3 nanocomposite film prepared by the present invention is in NaOH+NaCOOH solution, and when white light is irradiated, the potential of the 403 stainless steel electrode connected to it in 0.5M NaCl solution can be reduced to 450mV, which is far lower than the natural corrosion potential of stainless steel. The protective effect is remarkable. When the light is stopped, the potential of stainless steel rises to a certain extent, but it is still lower than the natural corrosion potential of stainless steel. The above results show that the SrTiO ₃ /TiO ₂ nano film prepared by the present invention has good photoelectric effect, especially exhibits excellent photogenerated cathodic protection effect on 403 stainless steel.

Description of drawings

Fig. 1 is a surface morphology (SEM) image of TiO ₂ and SrTiO ₃ nanocomposite films prepared in Example 1 of the present invention. In Fig. 1, (a) TiO ₂ , (b) SrTiO ₃ /TiO ₂ .

Fig. 2 is the photocurrent spectrum of the TiO ₂ and SrTiO ₃ nanocomposite films prepared in Example 1 of the present invention. In Fig. 2, curve (a) TiO ₂ , curve (b) SrTiO ₃ /TiO ₂ .

Fig. 3 is the time-varying curve of the electrode potential in 0.5M NaCl solution before and after illumination when 403 stainless steel is connected to different photoanodes in Example 1 of the present invention (on indicates illumination, off indicates turning off the light source, that is, dark state). In Figure 3, curve (a) TiO ₂ , curve (b) SrTiO ₃ /TiO ₂

Fig. 4 is a surface morphology (SEM) image of TiO ₂ and SrTiO ₃ nanocomposite films prepared in Example 2 of the present invention. In Fig. 4, (a) TiO ₂ , (b) SrTiO ₃ /TiO ₂ .

Fig. 5 is the photocurrent spectrum of TiO ₂ and SrTiO ₃ nanocomposite films prepared in Example 2 of the present invention. In FIG. 5 , curve (a) TiO ₂ , curve (b) SrTiO ₃ /TiO ₂ .

Fig. 6 is the time-varying curve of electrode potential in 0.5M NaCl solution before and after illumination when 403 stainless steel is connected to different photoanodes in Example 2 of the present invention (on indicates illumination, off indicates turning off the light source, that is, dark state). In FIG. 6 , curve (a) TiO ₂ , curve (b) SrTiO ₃ /TiO ₂ .

Detailed ways

Example 1

According to the above technical scheme (specific steps), a SrTiO ₃ nanocomposite film photoanode was prepared, and the cathodic protection effect of the photoanode on 403 stainless steel was tested.

Take a 0.1mm thick rectangular pure titanium foil as a sample (purity>99.7%), its length is 1.5cm, and its width is 1.0cm. Sequentially ultrasonic cleaning in acetone, absolute ethanol and deionized water for 30 min.

Composition of anodic oxidation solution: NH ₄ F content is 0.5wt%, glycerol: water (volume ratio) = 3:2. With titanium foil as anode and platinum sheet as cathode, anodize in the above solution for 1h. After the reaction was completed, it was washed with a large amount of deionized water, dried, and put into a muffle furnace for heat treatment at 450° C. for 120 minutes.

Put the prepared titanium foil covered with _TiO2 nanotube array film on the surface into a polytetrafluoroethylene reactor, add 0.01M Sr(OH) ₂ solution 40mL, react at 180°C for 0.5h, take out the sample at 0.01M Soaked in HCl solution for 1 min, then washed with a large amount of deionized water, dried and calcined in a muffle furnace at 450 °C for 120 min to obtain a SrTiO ₃ nanocomposite film with PN heterostructure composed of SrTiO ₃ and TiO ₂ .

Photocurrent test: A photocurrent spectrum measurement device consisting of a commercial optical system, electrochemical control system, data acquisition system and computer control system is used. The optical system consists of a light source, a monochromator, a chopper, and a quartz convex lens. 263A constant potential/galvanostat, 5210 dual-phase lock-in amplifier and photoelectrolytic cell constitute the electrochemical control and photocurrent signal acquisition system. In the photoelectrolytic cell of the three-electrode system, the TiO ₂ film or the SrTiO ₃ composite film was used as the photoanode, the saturated calomel electrode was used as the reference electrode, and the platinum wire was used as the auxiliary electrode. The 150W xenon lamp is used as the light source, the incident light is modulated by the monochromator, the chopper and the lens, and the incident light is irradiated vertically through the quartz window on the electrode surface of the TiO ₂ film or SrTiO ₃ composite film in the photoelectrolytic cell. The photocurrent was collected by a potentiostat and a lock-in amplifier.

The test of photogenerated cathodic protection effect of SrTiO ₃ nanocomposite film: TiO ₂ or SrTiO ₃ nanocomposite film was used as photoanode, placed in a photoelectrolytic cell containing 0.1M NaOH+0.1M NaCOOH solution. The protected 403 stainless steel was placed in the corrosion electrolytic cell as the working electrode, and the Pt electrode was used as the counter electrode, the saturated calomel electrode (SCE) was used as the reference electrode, and 0.5M NaCl solution was used as the corrosion medium. The photoanode and the stainless steel electrode are connected by wires, and the photoelectrolytic cell and the corrosion electrolytic cell are connected by a salt bridge (agar containing 1.0MKCl). When illuminating, a 150W high-pressure Xe lamp is used as a white light source, and is directly irradiated on the surface of the photoanode in the photoelectrolytic cell.

Figure 1 is the SEM image of the prepared TiO ₂ and SrTiO ₃ nanocomposite films. Comparing Figure 1(a) and Figure 1(b), it can be seen that the surface of the SrTiO ₃ composite film is more uniform than that of the pure TiO ₂ film, the tube wall becomes thicker, and a certain amount of SrTiO ₃ nanoparticles are attached to the surface of the TiO ₂ nanotubes .

Figure 2 is the photocurrent spectra of different nanofilms prepared. It can be seen from Figure 2(a) that for pure _TiO2 nanofilms, the maximum photocurrent value is 13 μA. When SrTiO ₃ was grown on the surface, the maximum photocurrent value of the composite film reached 19μA. After compounding SrTiO ₃ , the photocurrent value of the film increases significantly, mainly due to the formation of PN junction, which reduces the recombination probability of photogenerated electrons and holes, so that more electrons are transmitted to the external circuit.

Figure 3 is the electrode potential versus time curve of 403 stainless steel in 0.5M NaCl solution before and after connecting with pure TiO ₂ film and SrTiO ₃ composite film in the photoelectrolytic cell. As shown in Figure 3(a), when 403 stainless steel is connected to TiO ₂ , the electrode potential of 403 stainless steel drops rapidly by about 350mV; and when 403 stainless steel is connected to SrTiO ₃ composite film, the electrode potential of stainless steel can drop by 450mV under light. Comparing with TiO ₂ electrode, composite photoanode can increase the potential drop of 403 stainless steel electrode by 100mV. It shows that the SrTiO ₃ composite film prepared by the present invention has good photoelectric conversion effect. When the light source is cut off, the electrode potential value of the 403 stainless steel connected with the SrTiO ₃ composite film rises lower than that of the stainless steel connected with TiO ₂ . When the SrTiO ₃ composite film is illuminated again, the electrode potential of 403 stainless steel can still drop by 450mV, indicating that the composite film has good stability. The above results show that the SrTiO ₃ nanocomposite film prepared by the present invention exhibits excellent photogenerated cathodic protection effect.

Example 2

Take a 0.1mm thick rectangular pure titanium foil as a sample (purity>99.7%), which is 1.5cm long and 1.0cm wide. Sequentially ultrasonic cleaning in acetone, absolute ethanol and deionized water for 30 min.

Composition of anodic oxidation solution: NH ₄ F content is 0.5wt%, glycerol: water (volume ratio) = 3:2. With titanium foil as anode and platinum sheet as cathode, anodize in the above solution for 1h. After the reaction is finished, wash with a large amount of deionized water, dry and put it into a muffle furnace for heat treatment at 450°C for 120min.

Put the prepared titanium foil covered with _TiO2 nanotube array film on the surface into a polytetrafluoroethylene reaction kettle, add 0.01M Sr(OH) ₂ solution 40mL, react at 180°C for 1h, take out the sample and put it in 0.01M HCl solution Soaked in water for 1min, then rinsed with a large amount of deionized water, dried and calcined in a muffle furnace at 450°C for 120min. That is, a SrTiO ₃ nanocomposite film with PN heterostructure composed of SrTiO ₃ and TiO ₂ was prepared.

Photocurrent test: A photocurrent spectrum measurement device consisting of a commercial optical system, electrochemical control system, data acquisition system and computer control system is used. The optical system consists of a light source, a monochromator, a chopper, and a quartz convex lens. 263A constant potential/galvanostat, 5210 dual-phase lock-in amplifier and photoelectrolytic cell constitute the electrochemical control and photocurrent signal acquisition system. In the photoelectrolytic cell of the three-electrode system, the TiO ₂ film or the SrTiO ₃ composite film was used as the photoanode, the saturated calomel electrode was used as the reference electrode, and the platinum wire was used as the auxiliary electrode. The 150W xenon lamp is used as the light source, the incident light is modulated by the monochromator, the chopper and the lens, and the incident light is irradiated vertically through the quartz window on the electrode surface of the TiO ₂ film or SrTiO ₃ composite film in the photoelectrolytic cell. The photocurrent was collected by a potentiostat and a lock-in amplifier.

The test of photogenerated cathodic protection effect of SrTiO ₃ nanocomposite film: TiO ₂ or SrTiO ₃ nanocomposite film was used as photoanode, placed in a photoelectrolytic cell containing 0.1M NaOH+0.1M NaCOOH solution. The protected 403 stainless steel was placed in the corrosion electrolytic cell as the working electrode, and the Pt electrode was used as the counter electrode, the saturated calomel electrode (SCE) was used as the reference electrode, and 0.5M NaCl solution was used as the corrosion medium. The photoanode and the stainless steel electrode are connected by wires, and the photoelectrolytic cell and the corrosion electrolytic cell are connected by a salt bridge (agar containing 1.0MKCl). When illuminating, a 150W high-pressure Xe lamp is used as a white light source, and is directly irradiated on the surface of the photoanode in the photoelectrolytic cell.

Figure 4 is the SEM image of the prepared TiO ₂ and SrTiO ₃ composite film. Comparing Figure 4(a) and (b), it can be seen that the SrTiO ₃ nanocomposite film is smoother than the pure TiO ₂ film, and the thickness of the tube wall has increased, indicating that the SrTiO ₃ nanoparticles are distributed on the tube wall.

Figure 5 is the photocurrent spectrum of the prepared nano film. For pure TiO ₂ , the maximum photocurrent value is 13μA, see Figure 5(a). However, when SrTiO ₃ is formed on the surface of the film to form a composite film, the maximum photocurrent value can reach 17.5μA, as shown in Figure 5(b). It shows that SrTiO ₃ can significantly reduce the recombination probability of photogenerated electrons-holes and improve the photoelectric conversion efficiency of TiO ₂ .

Figure 6 is the electrode potential versus time curve of 403 stainless steel in 0.5M NaCl solution before and after connecting with pure TiO ₂ film and SrTiO ₃ composite film in the photoelectrolytic cell. As shown in Figure 6(a), when 403 stainless steel is connected to TiO ₂ , the electrode potential of 403 stainless steel drops rapidly by about 360mV after light exposure; while when 403 stainless steel is connected to SrTiO ₃ composite film, its electrode potential drops by about 480mV, see Figure 6(b). Compared with the pure TiO ₂ photoanode, the composite film photoanode can increase the potential drop range of 403 stainless steel electrode by 120mV. Illuminated again, at this time the electrode potential of the stainless steel dropped rapidly by 480mV, indicating that the prepared SrTiO ₃ composite film had good stability. After cutting off the light source, the electrode potential of 403 stainless steel rises, but at this time the potential of 403 stainless steel is still about 170mV lower than the original natural corrosion potential, and it is also lower than the stainless steel potential when it is connected with _TiO2 . The above results show that the SrTiO ₃ nanocomposite film prepared by the present invention has excellent photogenerated cathodic protection effect.

Claims (10)

1.SrTiO ₃the preparation method of nano composite membrane light anode is characterized in that comprising the following steps:

1) preparation of titanium matrix: using titanium foil as matrix, after ultrasonic the titanium matrix;

2) TiO ₂the preparation of film of Nano tube array: take the titanium matrix as anode, platinized platinum is negative electrode, after carrying out anodic oxidation reactions, cleans, and drying, calcining obtains TiO on the titanium matrix ₂film of Nano tube array;

3) SrTiO ₃the preparation of nano composite membrane light anode: by step 2) surface coverage prepared has TiO ₂the titanium matrix of film of Nano tube array is put into the polytetrafluoroethylene reactor, adds Sr (OH) ₂solution after reaction, soaks in HCl solution, cleans, and drying, calcining, obtain SrTiO ₃nano composite membrane light anode, this is the SrTiO with P-N heterostructure ₃/ TiO ₂composite material.

2. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 1), and the thickness of described titanium foil is 0.05～0.15mm, and length is 1.0～2.0cm, and width is 0.5～1.5cm, the purity of titanium foil>99.7%.

3. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 1), described ultrasonic be successively in acetone, absolute ethyl alcohol and deionized water for ultrasonic, the ultrasonic time is 25～40min.

4. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 2) in, the condition of described anodic oxidation reactions is: the electrolyte solution for anodic oxidation reactions contains NH ₄f(0.45～0.55) wt%, the ratio of glycerol and water is 3: (1～3), and the voltage of anodic oxidation reactions is 15～25V, the time of anodic oxidation reactions is 0.5～1.5h.

5. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 2) in, described cleaning adopts washed with de-ionized water.

6. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 2) in, described calcining is to calcine in Muffle furnace, and the temperature of calcining is 420～470 ℃, and the time of calcining is 100～150min.

7. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 3), described Sr (OH) ₂the addition of solution is 35～45mL, Sr (OH) ₂the concentration of solution is 0.005～0.015M.

8. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 3), and the temperature of described reaction is 160～200 ℃, and the time of reaction is 20～80min.

9. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 3), and the concentration of described HCl solution is 0.005～0.015M, and the time of described immersion is 0.5～1.5min.

10. SrTiO as claimed in claim 1 ₃the preparation method of nano composite membrane light anode, is characterized in that in step 3), and described cleaning adopts washed with de-ionized water; Described calcining can be calcined in Muffle furnace, and the temperature of calcining is 420～470 ℃, and the time of calcining is 100～150min.

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