Research And Material Development Of Photocatalytic PEM Battery Based On Humidity Difference

The use of clean and renewable energy has become an inevitable trend for future energy development.In addition to solar energy,wind energy,hydraulic energy and tidal energy and other energy sources,the humidity difference between different air areas is also a kind of energy with great potential.This energy has a wide spatial and temporal distribution in geographical environments,and is clean and stable.Therefore,in order to explore the utilization of the potential difference energy of humidity,in this paper we proposed a photocatalytic proton exchange membrane?PEM?battery based on humidity difference.However,this idea still faces many difficulties.In the reaction process involving the decomposition of water vapor,to construct a battery circuit and to ensure the migration of electrons are difficult.At the same time,the development of photocatalytic water splitting technology is still immature.Photocatalysts are faced with problems such as poor response to visible light,low separation efficiency of photogenerated electron-hole pairs and high cost.The photocatalytic proton exchange membrane battery based on humidity difference is brand-new and with huge development prospects.In order to explore feasible ways and research the key materials,the main research work of this paper is summarized as follows:?1?According to the theoretical analysis,the working principle of the photocatalytic PEM battery based on humidity difference and the feasible way to realize power generation were proposed,and the technical obstacles to be solved in order to realize this idea were listed and analyzed.?2?In view of the characteristics of large specific surface area,strong adsorption,and simple preparation process of the powdered catalytic material,Pt/TiO₂?Pt/Ti molar ratio=1%?,Ir O₂/TiO₂?Ir/Ti molar ratio=2:3?and Ir TiO_x?Ir O₂:TiO₂=2:3?were prepared sequentially by the sol-gel method,the melt reaction method and the proportional mixing method.The test results showed that Pt/TiO₂ had excellent photolysis water performance.In the online test,the amount of hydrogen evolution in photolysis of water reached 49.73?mol·h^-1.In the offline test,the amount of hydrogen evolution in pure water and saturated steam was 3.9?mol and 0.18?mol,respectively,indicating that Pt/TiO₂ had the potential in the direction of decomposing water vapor.However,the loose structure after the accumulation of powder materials can result in poor conductivity and light transmittance.Thus,it is not suitable for the catalytic reaction on the anode side of the power generation device.?3?In order to prepare TiO₂ with electrical conductivity,water absorption and photoelectric catalysis,a titanium dioxide nanotube array?TNTA?with uniform diameter,tube length and distribution was prepared by anodizing method using high-purity titanium sheet as substrate.After calcination,the photocurrent density of TNTA reached up to 2.6m A·cm^-2?under 0.5V applied voltage?.Further,in order to achieve the moisture permeability and light transmittance of the anode-side catalytic layer,a titanium mesh TNTA was prepared by anodizing method using a titanium mesh as substrate.And in this way,the combination of the catalytic layer and the collector layer was realized.The photo-deposition and electro-deposition methods were used to explore the loading of Pt on the surface of TNTA to improve the separation efficiency of photogenerated electron-hole pairs.?4?According to the proposed power generation principle,a battery operation experiment device was built,including the gas flow channels on the anode side and the cathode side,the lighting system and the data acquisition system.The assembly and testing of membrane electrodes will continue in the future.