Fe₂O₃/rGO Composite Material Micro-nano Structure Control And Its Photocatalytic And Electrochemical Performance

?-Fe₂O₃?Hematite?,a n-type semiconductor with narrow band gap?2.2 eV?,has a strong visible light absorption capacity.At the same time,it has been widely used in photocatalysis,gas sensors,magnetic recording materials,batteries,supercapacitors and many other fields because of its stable chemical performance,low price and environmental friendliness.A large number of experimental studies have shown that the morphology,size and dispersion of nanomaterials will affect their physical and chemical properties.Therefore,it is of great theoretical value and practical significance to prepare morphologically controllable nanostructures of?-Fe₂O₃ and to study their photocatalytic and electrochemical properties.In this paper,we mainly use hydrothermal/solvothermal method to prepare?-Fe₂O₃with different morphologies.We use micro-template method to make the basic components of iron oxide self-assemble into hollow structure,enhance its specific surface area in order to obtain more photocatalytic active sites to improve its photocatalytic activity,and study its growth mechanism.Then,we load iron oxide nanoparticles on graphene surface.Fe₂O₃/rGO composites with visible light response and high photocatalytic activity were prepared and their photocatalytic activity was studied.The full text mainly includes the following research contents:?1?Solvothermal method was used to prepare iron oxide with different morphology and structure by using different precipitators.Then the photocatalytic activity of iron oxide was investigated,and the basic unit with the highest activity of self-assembled structure was found:nanosheet.Subsequently,the hollow porous structure of iron oxide was formed by introducing ionic liquids as templates through microemulsion method.By controlling the amount of ionic liquids added,the effect of ionic liquids injection on its morphology and structure was investigated.Taking time as a variable,the growth mechanism of iron oxide hollow microspheres was investigated We also carried out visible-light photocatalytic degradation experiments of Rhodamine B on the prepared iron oxide porous spheres.The results showed that the samples had good photocatalytic performance and stability.In addition,the reason for the high photocatalytic activity of the samples was proposed by analyzing the absorption and desorption curves of nitrogen and the light absorption curves.To explore whether the magnetic validation sample can be recycled and reused.?2?Fe₂O₃/rGO composites were obtained by microwave hydrothermal method.The optimum photocatalytic environment and the effects of initial concentration of sample,initial PH and dye on photocatalytic performance were investigated in detail.The optimum initial concentration of Rh B was 20 mg/L,the amount of catalyst was 0.6 g/L,and the reaction pH was the initial pH value of RhB.The possible mechanism of photocatalytic reaction was proposed.?3?To investigate the electrochemical properties of Fe₂O₃/rGO composites,the specific capacity of the composites reaches 398 F/g?1 A/g?in the voltage range of-0.8-0.1 V,which is close to the theoretical specific capacity and has good rate performance.At the current density of 10 A/g,the specific capacity of the composites remains at 300F/g and the specific capacitance retention rate is as high as 75%.