Preparation of Ag@AgCl-doped TiO_2/sepiolite and its photocatalytic mechanism under visible light  

作　　者：Shaomin Liu Dinglong Zhu Jinglin Zhu Qing Yang Huijun Wu 

机构地区：[1]School of Earth Science and Environmental Engineering, Anhui University of Science and Technology

出　　处：《Journal of Environmental Sciences》2017年第10期43-52,共10页环境科学学报（英文版）

基　　金：supported by the Young and Middle-aged Academic Key Members of Anhui University of Science and Technology, the Doctor's degree Innovation Training Program (No. 2013bj1105);the International Cooperative Project of Anhui Province (No. 12030-603003)

摘　　要：A cube-like Ag@Ag Cl-doped TiO2/sepiolite（denoted Ag@Ag Cl–TiO2/sepiolite） was successfully synthesized via a novel method. X-ray diffraction, scanning electron microscopy, energy dispersion X-ray fluorescence, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy were performed to determine the structure and physicochemical properties of Ag@Ag Cl–TiO2/sepiolite. SEM micrographs revealed that Ag@Ag Cl nanoparticles and TiO2 film are well deposited on the surface of tube-like sepiolite. As a result, Ag@Ag Cl–TiO2/sepiolite exhibits a red shift relative to TiO2/sepiolite. Photocatalytic experiments demonstrated that the dosage of catalysts plays an important role during photocatalysis. The photoelectrochemical activities of Ag@Ag Cl–TiO2/sepiolite and TiO2/sepiolite were also investigated. Photocurrent responses confirmed that the ability of Ag@Ag Cl–TiO2/sepiolite to separate photo-generated electron–hole pairs is stronger than that of TiO2/sepiolite. Methylene Blue degradation is also improved under alkaline conditions and visible light irradiation because more UOH is produced by visible light excitation.This excellent catalytic ability is mainly attributed to the formed Ag nanoparticles and the Schottky barrier at the Ag/TiO2 interface. Active species analysis indicated that UO2-and h＋are implicated as active species in photocatalysis. Therefore, catalysts are excited to produce abundant electron–hole pairs after they absorb photons in photocatalysis.A cube-like Ag@Ag Cl-doped TiO2/sepiolite（denoted Ag@Ag Cl–TiO2/sepiolite） was successfully synthesized via a novel method. X-ray diffraction, scanning electron microscopy, energy dispersion X-ray fluorescence, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and diffuse reflectance ultraviolet–visible spectroscopy were performed to determine the structure and physicochemical properties of Ag@Ag Cl–TiO2/sepiolite. SEM micrographs revealed that Ag@Ag Cl nanoparticles and TiO2 film are well deposited on the surface of tube-like sepiolite. As a result, Ag@Ag Cl–TiO2/sepiolite exhibits a red shift relative to TiO2/sepiolite. Photocatalytic experiments demonstrated that the dosage of catalysts plays an important role during photocatalysis. The photoelectrochemical activities of Ag@Ag Cl–TiO2/sepiolite and TiO2/sepiolite were also investigated. Photocurrent responses confirmed that the ability of Ag@Ag Cl–TiO2/sepiolite to separate photo-generated electron–hole pairs is stronger than that of TiO2/sepiolite. Methylene Blue degradation is also improved under alkaline conditions and visible light irradiation because more UOH is produced by visible light excitation.This excellent catalytic ability is mainly attributed to the formed Ag nanoparticles and the Schottky barrier at the Ag/TiO2 interface. Active species analysis indicated that UO2-and h＋are implicated as active species in photocatalysis. Therefore, catalysts are excited to produce abundant electron–hole pairs after they absorb photons in photocatalysis.

关 键 词：Ag@AgCl Sepiolite Photocatalyst Photocurrent 

分 类 号：O643.36[理学—物理化学] TQ621.12[理学—化学]