The Construction Of Iron Oxide-based Heterojunction And Its Photocatalytic Performance

Photoelectrocatalysis?PEC?is an emerging technology which has been widely studied since the first discovery in the 1970s for effectively utilizing solar energy resources.There are two most eye-catching applications in PEC field.First,in the treatment of sewage,there are some advantages like high efficiency,simple process,environmentally friendly and non-toxic,relatively thorough products,etc.Especially in the degradation of organic pollutants,refractory antibiotics.The photodegradation shows a strong advantage and it is an ideal environmental treatment technology.Second,for the research of new energy,it can decompose water to prepare hydrogen and oxygen,reduce carbon dioxide as a small molecule fuel under the solar light irradiation,thus alleviate the energy crisis.In environmental treatment,the multi-phase Fenton technology based on iron oxides has become a research hotspot in wastewater treatment because of its environmental friendliness and simple operation,and it can produce strong oxidative hydroxyl radicals?·OH?to degrade organic pollutants,especially the strong destructive effect on the structure of antibiotics.Moreover,as a commonly used photocatalyst,iron oxide can generate hole electrons and trivalent iron ions under the excitation of light,which is helpful to improve the efficiency of solar photolysis of water.However,the short carrier diffusion length?2⁴nm?,low electron mobility(0.2 cm² V^-1 S^-1)and fast charge recombination??¹0 ps?of alpha-Fe₂O₃ lead to poor conductivity,short lifetime of excited state,fast charge recombination,causing its low degradation efficiency of organic pollutants and poor performance of water splitting,limiting its application in photocatalysis.Based on the above problems,we modified the iron oxide materials by forming various heterojunctions of iron oxide base,in order to enhance the absorption range of solar spectrum,inhibite the recombination of electrons and holes in the photocatalytic process,so that to improve the photocatalytic degradation or photocatalytic water-splitting performance of the materials.?1?Through the simple hydrothermal synthesis,the Fe₂O₃ powder is converted into Fe₂O₃/Fe₃O₄@FeP core-shell heterojunction by partial in-situ phosphating.The norfloxacin was then subjected to be photodegradated with the heterostructure materials.The test results show that under the 200 mW cm^-2 simulated irradiation by xenon lamp,the new Fenton-?-Fe₂O₃/Fe₃O₄@FeP/sunlight system can effectively degrade 80%of norfloxacin within 5 minutes.?2?First,tungsten trioxide?WO₃?was loaded on the surface of conductive glass by a simple hydrothermal reaction to form FTO-WO₃.Second,FeAA was decomposed by chemical vapor deposition at 500?.According to Fe?C₅H₇O₂?₃+O₂^??Fe₂O₃+CO+CO₂,the acetylacetone iron was first sublimated and deposited on the surface of FTO-WO₃,and then formed a thin layer of Fe₂O₃ by high temperature decomposition.The heterojunction of WO₃ and Fe₂O₃ loaded on FTO conductive glass is constructed to improve the photocurrent density of FTO-WO₃.