Study On Preparation And Performance Of New Type Photocatalysts

Photocatalysis technology possesses an unique advantage over environmental remediation.However,there are many disadvantages of low photocatalytic efficiency,bad quantum yield and diffcult separation.After synthesizing composite film and composite semiconductor,the problems of low photocatalytic efficiency and diffcult separation have been solved.TiO₂/Al?H₂PO₄?₃ composite film was synthesized via a spray method.The composite film exhibited higher photocatalytic activity compared with pure TiO₂?about1.4 fold?.TiO₂ nanoparticles were fixed on the framework of Al?H₂PO₄?₃,which could prevent the agglomeration of TiO₂ nanoparticles and increase the reactive sites.More than that,the composite film was separation-free and bears good washing resistance thanks to the good adhesive force of Al?H₂PO₄?₃.The good adhesive force could be ascribed to the formation of Ti-O-P bond between TiO₂ and Al?H₂PO₄?₃,which also contributed to the increased photocatalytic activity.The g-C₃N₄ nanosheets were prepared by chemical exfoliation method via concentrated sulfuric acid.BiPO₄/g-C₃N₄ photocatalysts were prepared by chemical adsorption method.The X-ray diffraction?XRD?,scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,UV-visible diffused reflectance spectroscopy?UV-vis DRS?and X-ray photoelectron spectroscopy?XPS?were used to study the microstructure and interface properties.It proved that BiPO₄/g-C₃N₄ photocatalysts were prepared successfully.5% BiPO₄/g-C₃N₄ photocatalyst exhibited the highest photocatalytic activity under ultraviolet light irradiation using methylene blue as the target pollutant.The photocatalytic activity of 5% BiPO₄/g-C₃N₄ is 1.72 times and 2times as high as that of pure BiPO₄ and P25 respectively.The enhancement of BiPO₄/gC₃N₄ photocatalyst can be attributed to the formation of core-shell structure,which benefits the separation between photoelectrons and holes.