Establishment Of Artificial Photosynthesis Device Based On Nitride And Study On The Perfoemance Of Electrodes

With the progress of the times,social development is also moving forward steadily.Good social environment has made a convenient and comfortable living environment for people.Modern prosperous life is based on all kinds of energy.At present,the main energy supply is fossil fuels.The exhaust gas from the combustion of fossil fuels is not cleaning treatment,and a large amount of CO₂ will be directly exhausted,resulting in serious greenhouse effect.With the progress of science and technology,the conversion of greenhouse gas CO₂ into useful industrial materials has begun to be realized.Photoelectric reduction of CO₂ is an environmentally friendly method.Using non-toxic and harmless inorganic materials is the best choice.In this paper,the research work is focused on the construction of fully sealed CO₂reduction device and the system of detection and analysis device.The reaction device is H-cell and the detection system is gas chromatography.The on-line detection and analysis of CO₂ reduction products can be realized by this system.In_xGa_1-xN/Ga N heterojunction is used as photoanode and In is used as cathode in the experiment.The reduction products is mainly CO,CH₄,C₂H₄,C₂H₆ and H₂ in different electrolyte environments.At the same time,the competitive reaction-hydrogen evolution reaction is very serious.H₂ was the main reaction product.In addition,the differences of photoelectric properties of In Ga N/Ga N heterojunctions with different In contents were studied.In_0.071Ga_0.929N/Ga N heterojunction reacts in Na OH-KCl and KHCO₃-KHCO₃solution systems respectively.It is found that the photoanode in Na OH-KCl system is easier to be etched,the photocurrent is larger,the cathode potential is higher,but the current stability is not good.In_0.009Ga_0.991N/Ga N heterojunctions react in Na OH-KCl and Na OH-KHCO₃solution systems respectively.It is found that the surface of the films reacted in Na OH-KHCO₃system is not etched and the current is large.In Na OH-KCl system,the films have been etched,but compared with the results of In_0.071Ga_0.929N/Ga N heterojunction reaction in Na OH-KCl system,the etching degree is lower and the reduction performance is better than that of In_0.071Ga_0.929N/Ga N heterojunction reaction in Na OH-KCl system.As the electrolyte for cathode and anode change,the types of reduction products and Faraday efficiencies will be change,and the degree of corrosion of photoanode varies with the diffrent types of electrolytes.The difference of crystal quality between photoanodes doped with different percentage of In seriously affects the stability of materials.It further affects the types of reduction products and Faraday efficiency.