The Preparation And Photocatalytic Performances Of Zinc Titanate-based Photocatalysts

With the development of the human beings,the increasingly serious problems of water pollution would be a large threat to the natural environment and the health of living things.Owing to the characteristics of high-efficiency and green,the photocatalysis techniques provide an effective way to solve the problems of environment and resources,catching researchers? eyes.As a typical of untraditional photocatalyst,ZnTiO₃ has a significant research value thanks to the excellent electrical and optical properties.In this paper,the pure phase of ZnTiO₃ was prepared at low temperature through an improving synthetic method,and further obtained the composite photocatalysts by the modifying of graphene oxide.A series of analytical techniques,containing XRD,SEM,BET,XPS,FT-IR,UV-vis,were used to characterize the crystallinity,crystalline sizes,morphology,specific surface area,pore size and absorption for solar energy of the samples,and methylene blue?MB?and tetracycline?TC?were used as the model contaminants to evaluate the performances of the prepared photocatalysts.The results are as follows:?1?The ZnTiO₃ was prepared through a sol-gel process.The spherical nanoparticles of ZnTiO₃ calcined at 600? for 2h,when the photodegradation rate of MB was 75.3% after light irradiation for 150 min,showed the pure phase and small crystalline sizes,which exhibited the optimal photocatalytic performances.?2?The GO/ZnTiO₃ composite photocatalysts were synthesized by a hydrothermal method.The characterizations analysis showed that GO was reduced during the hydrothermal process and r GO and ZnTiO₃ were combined with Ti-O-C bond,improving the agglomeration of ZnTiO₃,furthermore,the absorption spectrum of the composite photocatalysts had a significant red-shift and the absorption edge shifted towards the visible region.When the mass ratio of GO/ZnTiO₃ was 0.5%,the composite photocatalyst via the hydrothermal reaction at 100? for 24 h showed the best photocatalytic activity,and the degradation rate of MB reached the maximum value of 95.2%,compared to 63.9% by as-synthesized ZT after light irradiation for 150 min,and the largest rate constant was 0.018min-1,3.5 times larger than that of the bare ZT.?3?The contrast degradation experiments of MB and TC for ZnTiO₃ and the GO/ZnTiO₃ composite photocatalyst found that both of them showed the outstanding removal efficiencies for TC,even better than that of MB.The reusability tests indicated that the prepared photocatalysts exhibited good stability and had a good application potential.