Construction Of Immobilized Fe₂O₃/CuFe₂O₄|Cu Photocatalyst Composite Film For Organic Pollutant Degradation With Simultaneous Hydrogen Production

These problems of environmental pollution and energy shortage are being attracted by more and more people.In particular,due to the rapid developments of industrialization and urbanization,various organic pollutant wastewater is discharged into the natural environment in large quantities and the fossil fuels are seriously consumed,which seriously destroyed the natural environment and disturbed the ecosystem balance.To solve these problems,some technologies that can both produce sustainable clean energy and mitigate the environmental pollution are urgently needed.Hydrogen with high energy density is widely regarded as the preferred clean energy in the future.The photocatalysis,which can be driven under sunlight irradiation,has attracted widespread attention of researchers and is considered one of the most environmentally friendly technologies.With further research,it is found that the photocatalytic technology can not only remove the organic pollutants in wastewater,but also produce hydrogen,alleviating the energy crisis.Therefore,it is considered a promising technology for hydrogen production and environmental pollution mitigation.As a sustainable technology,the photocatalysis can efficiently convert solar energy into chemical energy.In recent years,many semiconductor materials have been widely used in photocatalysis.Specifically,this is because not only the light response range is broadened,but also the transfer of photon-generated carriers between materials is promoted in the Z-scheme photocatalytic system.In this way,the more negative reduction potential electrons and the more positive oxidation potential holes are retained,which makes the Z-scheme photocatalyst have stronger redox ability.At present,for most Z-scheme photocatalysts are still powdery,it is very inconvenient for the recovery and reuse of the photocatalysts.However,it is also not suitable for large-scale application.In order to overcome this disadvantage,in this experiment,an immobilized Z-scheme Fe₂O₃/Cu Fe₂O₄|Cu photocatalyst composite film can be prepared by sol-gel spin coating and incomplete solid-phase chemical reaction methods.We further solve the problem that most photocatalyst systems can only get mixed gas and the pure hydrogen can not be obtained.By selecting cheap raw materials and improving the preparation method,the designed immobilized photocatalyst composite film is more propitious to large-scale production.In designed photocatalyst composite film,the copper foil is not only the supporter of photocatalyst material,but also the electrode that participates in the hydrogen production reaction and facilitates the electron transfer.According to the unique structure of the designed immobilized photocatalyst composite film,the electrons generated in the photocatalytic reaction can be easily transferred to the other side surface of copper foil.The organic pollutants degradation and hydrogen production can be carried out on both sides of the copper foil,respectively,by using the designed photocatalyst composite film.Therefore,the H₂ and CO₂ can be collected separately on both sides of the photocatalyst composite film without needing further separation and purification.The morphology,structure and photoelectric properties of photocatalyst were studied by various characterization techniques.The effects of some significant conditions such as sol-spin coating layer number,calcination times and calcination temperatures on photocatalyst degradation with simultaneous hydrogen production were investigated.The results show that,after simulated sunlight irradiation 120 min,the immobilized Z-scheme Fe₂O₃/Cu Fe₂O₄|Cu photocatalyst composite film obtained at optimal conditions exhibits an excellent photocatalytic performance and the degradation ratio of crystal violet and hydrogen production reach 88.22%and 375.00μmol/dm~2,respectively.Cyclic experiments show that immobilized Z-scheme Fe₂O₃/Cu Fe₂O₄|Cu photocatalyst composite film owns good stability,which is wished that the immobilized Z-scheme Fe₂O₃/Cu Fe₂O₄|Cu photocatalyst composite film could be prepared industrially and then widely used to degrade organic pollutants and generate pure hydrogen on a large scale.The active species capture experiments and electron spin resonance（ESR）measurements confirm confirmed the action of the active substance.Finally,the possible mechanism of immobilized Z-scheme Fe₂O₃/Cu Fe₂O₄|Cu photocatalyst composite film has been proposed.