title: Efficient removal of radioactive iodide ions from water by three-dimensional Ag2O-Ag/TiO2 composites under visible light irradiation.
abstract: Three-dimensional Ag2O and Ag co-loaded TiO2 (3D Ag2O-Ag/TiO2) composites have been synthesized through a facile method, characterized using SEM, EDX, TEM, XRD, XPS, UV-vis DRS, BET techniques, and applied to remove radioactive iodide ions (I(-)). The photocatalytic adsorption capacity (207.6 mg/g) of the 3D Ag2O-Ag/TiO2 spheres under visible light is four times higher than that in the dark, which is barely affected by other ions, even in simulated salt lake water where the concentration of Cl(-) is up to 590 times that of I(-). The capability of the composites to remove even trace amounts of I(-) from different types of water, e.g., deionized or salt lake water, is demonstrated. The composites also feature good reusability, as they were separated after photocatalytic adsorption and still performed well after a simple regeneration. Furthermore, a mechanism explaining the highly efficient removal of radioactive I(-) has been proposed according to characterization analyses of the composites after adsorption and subsequently been verified by adsorption and desorption experiments. The proposed cooperative effects mechanism considers the interplay of three different phenomena, namely, the adsorption performance of Ag2O for I(-), the photocatalytic ability of Ag/TiO2 for oxidation of I(-), and the readsorption performance of AgI for I2.
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Shuaishuai
authors.initials: S
authors.lastname: Liu
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Yuchang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
authors.forename: Yaru
authors.initials: Y
authors.lastname: Li
authors.affiliation: CECEP Environmental Protection Investment Development Co., Ltd., Jiangxi 3300969, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Han
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China; Tianjin Co-Innovation Center of Chemical Science and Engineering, Tianjin 300072, China. Electronic address: naping@tju.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Na
mesh_terms: D000327:Adsorption; D007454:Iodides / Q000737:chemistry; D007457:Iodine Radioisotopes / Q000032:analysis*; D007700:Kinetics; D008027:Light; D008422:Materials Testing; D010087:Oxides / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010782:Photolysis; D018030:Silver Compounds / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014025:Titanium / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014867:Water / Q000737:chemistry; D014875:Water Pollutants, Radioactive / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D007454:Iodides; D007457:Iodine Radioisotopes; D010087:Oxides; D018030:Silver Compounds; D014875:Water Pollutants, Radioactive; D014867:Water; C009495:titanium dioxide; C040225:disilver oxide; D014025:Titanium; D010100:Oxygen
keywords: 3D Ag(2)O–Ag/TiO(2); Cooperative effects; Cyclic regeneration; Photocatalytic adsorption; Radioactive iodide