Synthesis And Photocatalytic Activity Investigation Of AlFeO₃ Nanoparticles

AlFeO₃ is a perovskite-type oxide material and displays piezoelectric,magnetoelectric and ferromagnetic properties at low temperature.In addition,AlFeO₃ is proved to be an important luminescence material which makes it have a good application prospect in optical material field.However,there are few studies on the photocatalytic properties of AlFeO₃ powders.AlFeO₃ powder will hopefully be an efficient semiconductor photocatalyst and environment friendly material compared to other lead-based perovskite-type oxide materials.Therefore,it is necessary to explore the photocatalytic activity of the AlFeO₃ powders.Perovskite-type AlFeO₃ powders are synthesized by a modified polyacrylamide gel route using different chelating agents at different pHs and calcination temperature.In the solution,N,N'-methylene-bisacrylamide were added with different ratio from acrylamide,bisacrylamide plays an important role in tailoring the particle size.X-ray diffraction?XRD?and Raman results indicate that the crystal structure of AlFeO₃ powders depend on the choice of chelating agents and calcination temperature.X-ray photoelectron spectroscopy?XPS?and SEM analysis indicate that the AlFeO₃ powders fabricated with oxalic acid at pH=7 have good phase purity and exhibit a finger-like aggregation shape and particle size of this sample is relatively large.However,AlFeO₃ powders prepared with the other four chelating agent exhibit an orthorhombic structure and the shapes are spheroidal.The scanning electron microscopic?SEM?images indicate that the morphology of the AlFeO₃ samples depend on the choice of chelating agent,pH value.Photocatalytic activities of the AlFeO₃ samples are determined by the degradation of rhodamine B dye in the presence of hydrogen peroxide and the results show that the samples will probably be applicable in the development of highly efficient photocatalyst.In addition,the rhombohedral Al FeO₃ samples exhibit better photocatalysis than the orthorhombic samples,which is probably because that the crystal structure of AlFe O₃ samples play a more important role than particle size in photocatalytic activity.AlFeO₃ samples synthesized at p H=10 exhibit better photocatalytic activity comparing with the samples synthesized at pH=7.As conformed by XPS,the better catalytic activity of AlFeO₃ samples synthesized at pH=10 may be partly attributed to the availability of more adsorbed oxygen on the surface of samples,thus generating more hydroxyl radicals.The as-prepared AlFeO₃ photocatalyst exhibits a pronounced photocatalytic activity for the decomposition of rhodamine B under visible-light irradiation,which is expected to widen the potential applications for perovskite-type oxide AlFeO₃.