TiOxNy nanobelt interwoven membrane, acidic electrolyzed water self-supporting oxygen evolution catalyst based on interwoven membrane and preparation method

Abstract

The invention discloses a TiOxNy nanobelt interlaced film, an acidic electrolyzed water self-supporting oxygen evolution catalyst based on the interlaced film and a preparation method, the TiOxNy nanobelt interlaced film is formed by TiOxNy nanobelts in an interlaced shape, the TiOxNy nanobelt interlaced film and IrRu alloy loaded on the interlaced film in a dipping mode form the catalyst, the loading capacity of the IrRu alloy is 10-20 wt%, the loading capacity of the IrRu alloy is 10-20 wt%, and the loading capacity of the IrRu alloy is 10-20 wt%. The molar ratio of Ir to Ru is (1: 4)-(4: 1). The TiOxNy nanobelt interwoven film has the advantages of high specific surface area, rapid electron transport and bubble escape, can still have excellent catalytic activity and stability under low IrRu alloy loading capacity, and ensures normal operation under high current density; the composite catalyst prepared by utilizing the TiOxNy nanobelt interwoven film shows remarkable stability within 200 hours under the conditions that the overpotential is 243-280mV in an acidic electrolyte and the current density is 100mA / cm < 2 >.

Description

Technical Field

[0001] The present invention belongs to the technical field of acidic electrolyzed water oxygen evolution electrodes, and particularly relates to a TiO x N y nanobelt interwoven membrane, a self-supporting oxygen evolution catalyst for acidic electrolyzed water based on the interwoven membrane, and a preparation method thereof. Background Art

[0002] At the current technical level, water electrolyzers mainly include alkaline electrolyzers and proton exchange membrane electrolyzers (PEMWE). Although PEMWE has many advantages such as higher voltage efficiency, lower ohmic loss, more compact system design, shorter startup time, higher power density and current density, fewer side reactions, and lower gas crossover compared with commercially mature alkaline electrolyzers, the harsh acidic and strongly oxidizing conditions pose a great challenge to the research and development of high-performance acidic oxygen evolution reaction (OER) catalysts.

[0003] Although IrRu alloy catalysts are considered to be the most promising acidic OER catalysts, the scarcity of metal Ir and the instability of metal Ru limit their large-scale application. The introduction of a support can effectively improve the dispersion of metal nanoparticles, increase the number of active sites, strongly interact with metal nanoparticles, regulate their electronic structure and stability, and ultimately improve the catalytic activity and stability of the catalyst and reduce the usage of noble metals. Therefore, supported IrRu catalysts are expected to achieve their large-scale application. However, as a support for IrRu acidic OER catalysts, it must have sufficient conductivity, antioxidant and corrosion resistance. Among them, TiO x N y simultaneously has the high conductivity of TiN and the high corrosion resistance of TiO2, and is considered to be an ideal support for IrRu catalysts. Previous studies have also confirmed that nanobelt-shaped TiO x N y can still have excellent catalytic activity and stability when the IrRu alloy has a low loading amount (the loading amount is only 10-30 wt%).

[0004] However, the existing acidic oxygen evolution reaction (OER) catalysts are basically in powder form. When using powder catalysts for PEMWE, the following technical defects still exist in the application process:

[0005] (1) Powder catalysts need to be coated on a conductive substrate using a binder, which affects the conductivity of the electrode and cannot achieve the normal operation of PEMWE at high current densities;

[0006] (2) It increases the overall weight of the electrode, makes the preparation process cumbersome, and reduces the power density of the electrolyzer;

[0007] (3) The use of the binder will reduce the effective active area of the catalyst, thereby blocking the mass transfer channels and inhibiting the bubble escape of electron transfer.

[0008] Based on this, there is a need to study an oxygen evolution electrode catalyst support that can avoid the use of a binder and still enhance the binding force and electron transfer ability between the catalyst and the substrate. Summary of the Invention

[0009] Object of the Invention: The technical problem to be solved by the present invention is to provide a TiO x N y nanobelt interwoven membrane, based on which a self-supporting oxygen evolution catalyst is formed, thereby avoiding the use of a binder, having a larger specific surface area, being able to better disperse the catalyst, and increasing its effective active area.

[0010] Technical Solution: The TiO x N y nanobelt interwoven membrane of the present invention is prepared by the following steps:

[0011] (1) Pour the sodium titanate nanobelt aqueous solution onto the filter membrane and perform suction filtration to form a sodium titanate nanobelt interwoven membrane;

[0012] (2) After performing ion exchange on the interwoven membrane with distilled water and nitric acid with a concentration of 0.5 - 0.8 mol / L for 0.5 - 2 h, separate it from the filter membrane through drying to obtain a hydrogen titanic acid nanobelt interwoven membrane;

[0013] (3) Place the hydrogen titanic acid nanobelt interwoven membrane under vacuum conditions, introduce NH3 gas, heat it to 600 - 700 °C and keep it warm for 2 - 8 h to prepare the TiO x N y nanobelt interwoven membrane, where x + y = 1, 0 ≤ x ≤ 1, 0 ≤ y ≤ 1.

[0014] Furthermore, in step (1) of the TiO x N y nanobelt interwoven membrane of the present invention, the sodium titanate nanobelt is prepared by the following steps: Disperse titanium dioxide powder in a sodium hydroxide solution with a concentration of 1 - 10 mol / L according to a mass - volume ratio of 1 g:(150 - 500) ml, react in an oven at 180 - 220 °C for 10 - 40 h, cool to room temperature, and obtain the sodium titanate nanobelt through centrifugation, washing, and drying.

[0015] Furthermore, in step (1) of the TiO x N y nanobelt interwoven membrane of the present invention, the pore diameter of the filter membrane is 0.2 - 0.4 μm.

[0016] Furthermore, in step (1) of the TiO x N yIn step (1) of the nanobelt interwoven film, the flow rate of NH3 gas introduced is 10 - 40 mL / min, and the heating rate is 5 - 10 °C / min.

[0017] The acidic electrolyzed water self-supporting oxygen evolution catalyst of the present invention, the oxygen evolution electrode includes the above-mentioned TiOxNy nanobelt interwoven film carrier and the IrRu alloy loaded on the carrier; the loading amount of the IrRu alloy is 10 - 20 wt%, and the molar ratio of Ir to Ru is (1:4) - (4:1).

[0018] TiO of the present invention x N y The nanobelt interwoven film forms a film by self-interweaving of nanobelts as a carrier, which has a larger specific surface area to better disperse the powder catalyst, improve its effective active area, promote electron transmission, transfer and bubble overflow, and at the same time effectively reduce the amount of precious metal used and obtain a low-loading precious metal. In addition, when the catalyst loaded based on this carrier is applied to the oxygen evolution electrode, it can avoid using a binder, form a self-supporting method to combine with the electrode substrate, and then form a self-supporting oxygen evolution electrode with high OER activity and stability, and ensure its normal operation at a high current density.

[0019] The method for preparing the above acidic electrolyzed water self-supporting oxygen evolution catalyst of the present invention includes the following steps:

[0020] (1) Uniformly mix the anhydrous ethanol solution of iridium chloride and the ethanol solution of ruthenium chloride to obtain a mixed solution;

[0021] (2) Immerse the TiO x N y nanobelt interwoven film in the mixed solution for at least 24 h, suck out the excess liquid and then air-dry it naturally; the addition amount of the TiO x N y nanobelt interwoven film is 4 - 9 times the total mass of the metals in iridium chloride and ruthenium chloride;

[0022] (3) Place the air-dried TiO x N y nanobelt interwoven film in a vacuum environment, introduce Ar / H2 gas, and heat it to 350 - 450 °C and keep it warm for 1 - 4 h to obtain the oxygen evolution electrode.

[0023] Furthermore, in step (1) of preparing the oxygen evolution catalyst of the present invention, the concentration of the anhydrous ethanol solution of iridium chloride is 2 - 6 mmol / L; the concentration of the ethanol solution of ruthenium chloride is 2 - 6 mmol / L.

[0024] Furthermore, in step (1) of preparing the oxygen evolution catalyst of the present invention, the molar ratio of Ir / Ru in iridium chloride and ruthenium chloride is (1:4) - (4:1).

[0025] Furthermore, in step (3) of preparing the oxygen evolution catalyst of the present invention, the flow rate of the Ar / H2 gas introduced is 10-20 mL / min, and the heating rate is 2-5 °C / min.

[0026] Beneficial effects: Compared with the prior art, the significant advantages of the present invention are as follows: TiO x N y The nanobelt interwoven film has the advantages of high specific surface area, fast electron transport, and bubble escape, and can achieve excellent catalytic activity and stability even at a low IrRu alloy loading (only 10-20 wt%), and ensure its normal operation at a high current density; by using TiO x N y The IrRu / TiO x N y nanobelt interwoven film oxygen evolution catalyst can have an overpotential of 243-280 mV at a current density of 100 mA / cm 2 in an acidic electrolyte, and show significant stability within 200 hours, and the increase in potential can be ignored. Description of the Drawings

[0027] Figure 1 SEM photograph of the TiO x N y nanobelt interwoven film carrier of Example 1 of the present invention;

[0028] Figure 2 XRD pattern of the IrRu / TiO x N y nanobelt interwoven film oxygen evolution catalyst of Example 1 of the present invention;

[0029] Figure 3 TEM photograph and elemental distribution of the IrRu / TiO x N y nanobelt interwoven film oxygen evolution catalyst of Example 1 of the present invention;

[0030] Figure 4 LSV curve graph of OER of the IrRu / TiO x N y nanobelt interwoven film oxygen evolution catalyst of Example 1 of the present invention and commercial IrO2 catalyst;

[0031] Figure 5 Stability test of OER of the IrRu / TiO x N y nanobelt interwoven film oxygen evolution catalyst of Example 1 of the present invention and commercial IrO2 catalyst. Detailed Embodiments

[0032] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0033] It should be noted that the raw material titanium dioxide powder used in the present invention is anatase-type nano-titanium dioxide (15 - 50 nm), commercial P25 or photocatalyst anatase nano-titanium oxide powder (5 nm). Other raw materials can be purchased commercially, where the purity of NH3 is 99.9%; the purity of iridium chloride is ≥99.8%; the purity of ruthenium chloride is ≥99.8%.

[0034] Example 1

[0035] The TiO x N y nanobelt interwoven film of this Example 1 is prepared by the following steps:

[0036] (1) 0.1 g of P25 powder is dispersed in 40 mL of 10 mol / L sodium hydroxide solution, transferred to the polytetrafluoroethylene liner of a 100 mL hydrothermal autoclave, and then sealed. It is placed in an oven at 200 °C for reaction for 25 h, cooled to room temperature, centrifuged, washed and dried to obtain sodium titanate nanobelts;

[0037] (2) The sodium titanate nanobelts are added to water to form a uniform suspension, and then the aqueous solution of sodium titanate nanobelts is poured onto a filter membrane with a pore size of 0.3 μm, and a sodium titanate nanobelt interwoven film is formed by simple suction filtration;

[0038] (3) The interwoven film is subjected to ion exchange with distilled water and 0.5 mol / L nitric acid for 2 h, and then dried overnight in an oven at 50 °C, and separated from the filter membrane to obtain a hydrogen titanate nanobelt interwoven film;

[0039] (4) The hydrogen titanate nanobelt interwoven film is placed in a tubular furnace, and NH3 is introduced at a gas flow rate of 15 mL / min under vacuum conditions, and the temperature is raised to 600 °C at a heating rate of 6 °C / min, held for 2 h, and cooled to room temperature to obtain the TiO x N y nanobelt interwoven film.

[0040] Using the TiO x N y nanobelt interwoven film to continue preparing an IrRu / TiO x N y nanobelt interwoven film oxygen evolution catalyst. This catalyst includes the above TiO x N y nanobelt interwoven film and the IrRu alloy loaded on this carrier. The loading amount of this alloy is 15 wt%, and the molar ratio of Ir to Ru is 1:3. The specific preparation steps are as follows:

[0041] (1) Mix 10 mL of 2 mmol / L iridium chloride anhydrous ethanol solution and 10 mL of 6 mmol / L ruthenium chloride ethanol solution evenly (Ir / Ru molar ratio is 1:3);

[0042] (2) Immerse the TiO x N y nanobelt interwoven membrane in the above solution, and the mass of the TiO x N y nanobelt interwoven membrane is 17 / 3 times the total mass of metals in iridium chloride and ruthenium chloride (i.e., the noble metal loading is 15 wt%), take it out after standing for 24 h, blot the excess liquid, and dry it naturally;

[0043] (3) Place the dried interwoven membrane in a tubular furnace, evacuate, then introduce Ar / H2 at a gas flow rate of 15 mL / min, heat it to 400 °C at a heating rate of 2 °C / min, hold for 2 h, and cool to room temperature to obtain the IrRu / TiO x N y nanobelt interwoven membrane oxygen evolution catalyst.

[0044] Structure characterization 1 - TiO x N y nanobelt interwoven membrane

[0045] Figure 1 is the SEM photograph of the TiO x N y nanobelt interwoven membrane prepared in Example 1 of the present invention. It can be seen from the figure that the simple filtration method adopted can indeed form an interwoven membrane with good interwoven state, and after nitridation treatment, the banded structure of the hydrogen titanate nanobelts can be effectively retained, and the interwoven state of the interwoven membrane will not be damaged.

[0046] Composition characterization 2 - IrRu / TiO x N y nanobelt interwoven membrane oxygen evolution catalyst

[0047] Figure 2 is the XRD pattern of the IrRu / TiOxNy nanobelt interwoven membrane oxygen evolution catalyst prepared in Example 1 of the present invention. From Figure 2 it can be seen that the IrRu / TiO x N y nanobelt interwoven membrane prepared from hydrogen titanate nanobelts shows the characteristic peaks of the (111), (200), (220) and (311) crystal planes of TiO x N y , indicating that it no longer contains the hydrogen titanate phase and is completely converted into TiO x N yIn addition, the weak peaks at 38.6°, 41.8°, 43.8°, 57.9°, 69.5°, 78.4° and 84.8° correspond to the (100), (002), (101), (102), (110), (103) and (112) planes of hexagonal close-packed (hcp) IrRu, indicating the successful loading of the alloy.

[0048] Structural Characterization of 3-IrRu / TiO x N y Nanobelt Interwoven Membrane Oxygen Evolution Catalyst

[0049] Figure 3 For the IrRu / TiO prepared in Example 1 of the present invention x N y TEM photo of the nanobelt interwoven membrane composite catalyst. As can be seen from the figure, the alloy particles obtained by the impregnation reduction method are uniform in size and evenly dispersed on the carrier.

[0050] Performance Detection of IrRu / TiO x N y Nanobelt Interwoven Membrane Oxygen Evolution Catalyst

[0051] The IrRu / TiO prepared in this Example 1 x N y The nanobelt interwoven membrane oxygen evolution catalyst was respectively tested for OER catalytic activity and stability. The IrRu / TiO nanobelt interwoven membrane oxygen evolution catalyst prepared by the present invention x N y When preparing the electrode, the nanobelt interwoven membrane oxygen evolution catalyst does not need to be sprayed onto the electrode substrate plate with an adhesive, but can be bonded and fixed to the electrode substrate plate by hot pressing. To evaluate the stability of the electrocatalyst, time-potential measurements were carried out at a constant current density of 100 mA cm -2 for 200 h. The test results are as Figure 4 and Figure 5 shown. As can be seen from Figure 4 , in acidic electrolyte, at a current density of 100 mA / cm 2 , the overpotential is 243 mV, which is significantly better than that of commercial IrO2 (317 mV) with the same loading; it shows remarkable stability within 200 hours, and the increase in potential can be ignored, which is significantly better than commercial IrO2 (40 h).

[0052] Example 2

[0053] The TiO of this Example 2 x N y nanobelt interwoven membrane was prepared by the following steps:

[0054] (1) 0.1 g of anatase-type nanoscale titanium dioxide was dispersed in 50 mL of 5 mol / L sodium hydroxide solution, transferred to the polytetrafluoroethylene liner of a 100 mL hydrothermal autoclave, sealed, placed in an oven at 220 °C for reaction for 15 h, cooled to room temperature, centrifuged, washed and dried to obtain sodium titanate nanoribbons;

[0055] (2) The sodium titanate nanoribbons were added to water to form a uniform suspension, and then the aqueous solution of sodium titanate nanoribbons was poured onto a filter membrane with a pore size of 0.2 μm, and a sodium titanate nanoribbon interwoven membrane was formed by simple suction filtration;

[0056] (3) The interwoven membrane was subjected to ion exchange with distilled water and 0.8 mol / L nitric acid for 0.5 h, and then dried overnight in an oven at 50 °C, and separated from the filter membrane to obtain a hydrogen titanate nanoribbon interwoven membrane;

[0057] (4) The hydrogen titanate nanoribbon interwoven membrane was placed in a tubular furnace, and NH3 was introduced at a gas flow rate of 20 mL / min under vacuum conditions, and heated to 660 °C at a heating rate of 6 °C / min, held for 6 h, and cooled to room temperature to obtain a TiO x N y nanoribbon interwoven membrane.

[0058] Using the TiO x N y nanoribbon interwoven membrane to continue to prepare an IrRu / TiO x N y nanoribbon interwoven membrane composite catalyst, which includes the above TiO x N y nanoribbon interwoven membrane and an IrRu alloy supported on this carrier, the loading amount of this alloy is 10 wt%, and the molar ratio of Ir to Ru is 1:1. The specific preparation steps are as follows:

[0059] (1) 10 mL of a 2 mmol / L anhydrous ethanol solution of iridium chloride and 10 mL of a 2 mmol / L ethanol solution of ruthenium chloride were mixed evenly (Ir / Ru molar ratio is 1:1);

[0060] (2) The TiO x N y nanoribbon interwoven membrane was immersed in the above solution, and the mass of the TiO x N y nanoribbon interwoven membrane was 9 times the total mass of the metals in iridium chloride and ruthenium chloride (i.e., the noble metal loading amount is 10 wt%). After standing for 24 h, it was taken out, excess liquid was blotted dry, and air-dried naturally;

[0061] (3) Place the dried intertwined film in a tubular furnace. After evacuating, introduce Ar / H₂ at a gas flow rate of 15 mL / min and heat it to 350 °C at a heating rate of 2 °C / min, hold for 4 h, and then cool to room temperature to obtain the IrRu / TiOxNy nanobelt intertwined film composite catalyst.

[0062] Performance detection

[0063] The TiO prepared in this example x N y nanobelt intertwined film and the IrRu / TiO x N y nanobelt intertwined film composite catalyst were detected: the carrier was completely converted into TiO x N y , and the alloy was successfully loaded; the IrRu / TiO x N y nanobelt intertwined film composite catalyst was hot-pressed with the electrode substrate to prepare an electrode. In an acidic electrolyte at a current density of 100 mA / cm 2 , the overpotential was 271 mV, and it showed significant stability within 200 hours, and the increase in potential was negligible.

[0064] Example 3

[0065] The preparation method of the TiO x N y nanobelt intertwined film in this Example 3 is as follows:

[0066] (1) Disperse 0.3 g of photocatalyst anatase titanium oxide powder in 60 mL of 8 mol / L sodium hydroxide solution, transfer it to the polytetrafluoroethylene inner liner of a 100 mL hydrothermal autoclave, seal the autoclave, place it in an oven at 220 °C for reaction for 25 h, cool to room temperature, centrifuge, wash and dry to obtain sodium titanate nanobelts;

[0067] (2) Add the sodium titanate nanobelts to water to form a uniform suspension, and then pour the sodium titanate nanobelt aqueous solution onto a filter membrane with a pore size of 0.4 μm, and form a sodium titanate nanobelt intertwined film by simple suction filtration;

[0068] (3) Carry out ion exchange on the intertwined film with distilled water and 0.6 mol / L nitric acid for 1 h, and then dry it overnight in an oven at 50 °C, and separate it from the filter membrane to obtain a hydrogen titanate nanobelt intertwined film;

[0069] (4) Place the hydrogen titanate nanobelt intertwined film in a tubular furnace, introduce NH₃ at a gas flow rate of 20 mL / min under vacuum conditions, and heat it to 600 °C at a heating rate of 6 °C / min, hold for 6 h, and cool to room temperature to obtain the TiO x N y nanobelt intertwined film.

[0070] Using TiO x N y nanobelt interwoven membrane to continue to prepare IrRu / TiO x N y nanobelt interwoven membrane composite catalyst, which includes the above TiO x N y nanobelt interwoven membrane and IrRu alloy supported on the carrier. The loading amount of the alloy is 20wt%, and the molar ratio of Ir to Ru is 3:1. The specific preparation steps are as follows:

[0071] (1) Mix 10 mL of 6 mmol / L iridium chloride anhydrous ethanol solution and 10 mL of 2 mmol / L ruthenium chloride ethanol solution evenly (Ir / Ru molar ratio is 3:1);

[0072] (2) Immerse the TiO x N y nanobelt interwoven membrane in the above solution, and the mass of the TiO x N y nanobelt interwoven membrane is 9 times the total mass of the metals in iridium chloride and ruthenium chloride (i.e., the noble metal loading is 10wt%). After standing for 24 h, take it out, blot dry the excess liquid, and air dry it;

[0073] (3) Place the air-dried interwoven membrane in a tubular furnace, evacuate, and then introduce Ar / H2 at a gas flow rate of 15 mL / min, and heat it to 450 °C at a heating rate of 2 °C / min, hold for 2 h, and cool to room temperature to obtain the IrRu / TiOxNy nanobelt interwoven membrane composite catalyst.

[0074] Performance detection

[0075] The TiO x N y nanobelt interwoven membrane and IrRu / TiO x N y nanobelt interwoven membrane composite catalyst prepared in this example were detected: the carrier was completely converted into TiO x N y , and the alloy was successfully loaded; the IrRu / TiO x N y nanobelt interwoven membrane oxygen evolution catalyst was hot-pressed with an electrode substrate to form an electrode. In an acidic electrolyte, at a current density of 100 mA / cm 2 , the overpotential was 259 mV, and it showed significant stability within 200 hours, and the increase in potential was negligible.

[0076] Example 4

[0077] The TiO x Ny The preparation method of the nanobelt intertwined membrane is as follows:

[0078] (1) Disperse 0.4 g of P25 powder in 60 mL of 10 mol / L sodium hydroxide solution, transfer it to the polytetrafluoroethylene liner of a 100 mL hydrothermal reactor, seal the reactor, place it in an oven at 200 °C for reaction for 30 h, cool to room temperature, centrifuge, wash and dry to obtain sodium titanate nanobelts;

[0079] (2) Add the sodium titanate nanobelts into water to form a uniform suspension, then pour the sodium titanate nanobelt aqueous solution onto a filter membrane with a pore size of 0.4 μm, and form a sodium titanate nanobelt intertwined membrane through simple suction filtration;

[0080] (3) Carry out ion exchange on the intertwined membrane with distilled water and 0.8 mol / L nitric acid for 1.5 h, and then dry it overnight in an oven at 50 °C, and separate it from the filter membrane to obtain a hydrogen titanic acid nanobelt intertwined membrane;

[0081] (4) Place the hydrogen titanic acid nanobelt intertwined membrane in a tube furnace, introduce NH3 at a gas flow rate of 15 mL / min under vacuum conditions, heat it to 600 °C at a heating rate of 6 °C / min, keep it warm for 6 h, and cool to room temperature to obtain a TiO x N y nanobelt intertwined membrane support.

[0082] Use the TiO x N y nanobelt intertwined membrane to continue preparing an IrRu / TiO x N y nanobelt intertwined membrane composite catalyst, which includes the above-mentioned TiO x N y nanobelt intertwined membrane and the IrRu alloy supported on this carrier. The loading amount of this alloy is 15 wt%, and the molar ratio of Ir to Ru is 1:2. The specific preparation steps are as follows:

[0083] (1) Mix 10 mL of 2 mmol / L iridium chloride anhydrous ethanol solution and 10 mL of 4 mmol / L ruthenium chloride ethanol solution evenly (Ir / Ru molar ratio is 1:2);

[0084] (2) Immerse the TiO x N y nanobelt intertwined membrane in the above solution, and the mass of the TiO x N y nanobelt intertwined membrane is 17 / 3 times the total mass of metals in iridium chloride and ruthenium chloride (i.e., the noble metal loading is 15 wt%). Take it out after standing for 24 h, blot the excess liquid, and air dry it;

[0085] (3) Place the dried intertwined membrane in a tubular furnace. After evacuating the air, introduce Ar / H₂ at a gas flow rate of 15 mL / min, and heat it to 450 °C at a heating rate of 2 °C / min. Keep it at this temperature for 1 h, and then cool it to room temperature to obtain IrRu / TiO x N y nanobelt intertwined membrane acidic electrolyzed water IrRu / TiO x N y nanobelt intertwined membrane composite catalyst.

[0086] Performance detection

[0087] The TiO x N y nanobelt intertwined membrane and IrRu / TiO x N y nanobelt intertwined membrane was detected: the carrier was completely converted into TiO x N y , and the alloy was successfully loaded; IrRu / TiO x N y nanobelt intertwined membrane catalyst was hot-pressed with an electrode substrate to prepare an electrode. In an acidic electrolyte, at a current density of 100 mA / cm 2 , the overpotential was 263 mV, and it showed significant stability within 200 hours, and the increase in potential was negligible.

[0088] In addition to the above embodiments of the present invention, for IrRu / TiO x N y nanobelt intertwined membrane composite catalyst, the molar ratio of Ir to Ru is in the range of (1:4)-(4:1), and the IrRu alloy loading is in the range of 10-20 wt%, and all have excellent OER catalytic activity and stable performance. Therefore, the example part will not be listed separately.

[0089] In addition to the above embodiments, it should be noted that nitric acid with a concentration of 0.5-0.8 mol / L is used in the present invention for ion exchange of the intertwined membrane. If the nitric acid concentration is too high, the nanobelt structure will be damaged; if the nitric acid concentration is too low, the exchange will be incomplete; the ion exchange time can be 0.5-2 h. In the process of preparing the acidic electrolyzed water self-supported oxygen evolution catalyst, the Ar / H₂ gas used is a commercially available ordinary Ar / H₂ gas, and there are no special requirements.

[0090] Moreover, by adopting the process parameters defined in the present invention, the technical effects claimed above in this application can be obtained. Therefore, there is no need to conduct experiments one by one for verification.

Claims

1. A TiO x N y nanobelt intertwined film, characterized in that, It is prepared by the following steps: (1) Pour the aqueous solution of sodium titanate nanobelts onto a filter membrane, and perform suction filtration to form an intertwined membrane of sodium titanate nanobelts; (2) Use distilled water and nitric acid with a concentration of 0.5 - 0.8 mol / L to perform ion exchange on the intertwined membrane for 0.5 - 2 h, then separate it from the filter membrane by drying to obtain an intertwined membrane of hydrotitanic acid nanobelts; (3) Place the hydrogen titanate nanobelt intertwined film under vacuum conditions, introduce NH3 gas, heat it to 600 - 700 °C and keep it warm for 2 - 8 h to obtain a TiO x N y nanobelt intertwined film, where x + y = 1, 0 ≤ x ≤ 1, 0 ≤ y ≤ 1.

2. The TiO x N y nanobelt intertwined film according to claim 1, characterized in that In step (1), the sodium titanate nanobelts are prepared by the following steps: Dissolve titanium dioxide powder in sodium hydroxide solution with a concentration of 1 - 10 mol / L according to the mass - volume ratio of 1 g:(150 - 500) mL, react in an oven at 180 - 220 °C for 10 - 40 h, cool to room temperature, and obtain the sodium titanate nanobelts after centrifugation, washing and drying.

3. The TiO x N y nanobelt intertwined film according to claim 1, characterized in that In step (1), the pore size of the filter membrane is 0.2 - 0.4 μm.

4. The TiO x N y nanobelt intertwined film, characterized in that In step (1), the flow rate of NH3 gas introduced is 10 - 40 mL / min, and the heating rate is 5 - 10 °C / min.

5. An acidic electrolyzed water self-supporting oxygen evolution catalyst, characterized in that, The oxygen evolution catalyst includes the TiOxNy nanobelt intertwined membrane support of claim 1 and the IrRu alloy supported on the support; the loading amount of the IrRu alloy is 10 - 20 wt%, and the molar ratio of Ir to Ru is (1:4) - (4:1).

6. A method for preparing the self-supported oxygen evolution catalyst of acidic electrolyzed water according to claim 5, characterized in that, It includes the following steps: (1) Uniformly mix the anhydrous ethanol solution of iridium chloride and the ethanol solution of ruthenium chloride to obtain a mixed solution; (2) Immerse the TiO x N y nanobelt intertwined film in the mixed solution for at least 24 h, suck out the excess liquid and then air-dry naturally; the addition amount of the TiO x N y nanobelt intertwined film is 4 - 9 times the total mass of metals in iridium chloride and ruthenium chloride; (3) Place the dried TiO x N y nanobelt intertwined film in a vacuum environment, introduce Ar / H2 gas, and heat it up to 350 - 450 °C for heat preservation reaction for 1 - 4 h to obtain the oxygen evolution catalyst.

7. The method for preparing the self-supporting oxygen evolution catalyst for acidic electrolyzed water according to claim 6, wherein In step (1), the concentration of the anhydrous ethanol solution of iridium chloride is 2 - 6 mmol / L; the concentration of the ethanol solution of ruthenium chloride is 2 - 6 mmol / L.

8. The method for preparing the acidic electrolyzed water self-supported oxygen evolution catalyst according to claim 6, characterized in that, In step (1), the molar ratio of Ir / Ru in iridium chloride and ruthenium chloride is (1:4) - (4:1).

9. The method for preparing the self-supported oxygen evolution catalyst of acidic electrolyzed water according to claim 6, wherein In step (3), the flow rate of Ar / H2 gas introduced is 10 - 20 mL / min, and the heating rate is 2 - 5 °C / min.

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