Study On Fe₂O₃ Catalysts In The Reaction Of Solar Concentrated Photocatalytic Reduction Of CO₂

The energy crisis and environmental issues make people pay more and more attention to solar energy,but the energy density of ordinary solar energy is low and cannot be directly and efficiently used.Therefore,the solar concentrating technology is considered to greatly increase the solar energy density per unit area.In this paper,the photocatalytic reduction of CO₂ was studied in the solar concentrating photocatalytic reaction system.The system can provide sufficient light intensity,temperature?200-1000 ^oC?,and pressure for the photocatalytic reaction,so as to achieve high efficiency and high yield of the photocatalytic reaction.?1?Metal oxide catalysts such as?-Fe₂O₃ were prepared by anodic oxidation method.The samples were characterized by FE-SEM,XRD,XPS,and UV-vis before and after the photocatalytic reaction.Finally,the catalyst was tested for solar photocatalytic reaction.Photocatalytic activity in the device.And the experimental results show that concentrating light improves the efficiency of photocatalytic reduction of CO₂,is not only by increasing the light intensity,temperature and pressure during the reaction,but also the environment in the reactor?formed under the condensing conditions during the reaction?also affected the structure and crystal form of the catalyst,and its crystallinity and photoluminescence properties are changed,and the reaction efficiency of photocatalytic reduction of CO₂ is finally improved.An?-Fe₂O₃/Fe₃O₄ heterojunction was formed under high light and heat conditions after the light was collected,which effectively activated the?-Fe₂O₃thin-film catalyst,thereby obtaining a much higher hydrocarbon yield than currently available.The conversion rate of CH₄ is about 800?mol·g^-1·h^-1,and the activity is best when the concentration ratio is 600?T=560 ^oC?.?2??-Fe₂O₃,Fe₃O₄,?-Fe₂O₃/Fe₃O₄ photocatalysts were prepared by the solvothermal method.According to the experimental results,it was found that the reaction system for solar photocatalytic reduction of CO₂ by solar concentrating is beneficial to the metal oxide semiconductor catalysts?-Fe₂O₃ and Fe₃O₄ for photocatalytic reduction of CO₂.The combination of?-Fe₂O₃ and Fe₃O₄ to prepare a photocatalyst with a heterojunction structure will increase its ability to photocatalytically reduce CO₂,expand the visible light absorption range,and increase solar energy utilization.Through the characterization of the catalyst samples,we found that we prepared the heterojunction catalysts containing?-Fe₂O₃ and Fe₃O₄crystal phases by solvothermal method in addition to the?-phase Fe₂O₃ and Fe₃O₄.