title: Synergistic photosensitized removal of Cr(VI) and Rhodamine B dye on amorphous TiO2 under visible light irradiation.
abstract: Amorphous TiO(2) (Am-TiO(2)) was prepared at room temperature by hydrolysis of Ti(OBu)(4) in water without addition of strong acids or organic solvents. Results from XRD and TEM revealed that the as-prepared Am-TiO(2) was composed of amorphous structure. For the simultaneous photosensitized removal of Cr(VI) and zwitterionic Rhodamine B (RhB) dye, Am-TiO(2) exhibited more significant synergistic effect than commercial P25-TiO(2). The removal efficiencies for RhB and Cr(VI) after 100 min visible light irradiation were 97.8% and 53.5% on Am-TiO(2), respectively. While 88.2% RhB and 42.1% Cr(VI) were removed on P25-TiO(2). Decreased synergistic activities as well as smaller surface areas were observed when Am-TiO(2) was pretreated at high temperatures (200-700°C). Thus, it was the larger specific surface area rather than better crystallinity dominated the synergistic degradation dynamics under visible light irradiation with lower pH (2), greater catalyst loading amount (2g/L), proper RhB/Cr(VI) ratios (1:8) and higher light intensity (500 W). Better synergistic performance was also obtained on Am-TiO(2) than P25-TiO(2) when Cr(VI) coexists with cationic dyes, while negligible difference was observed in the presence of anionic dyes. Superior stability and simplicity of Am-TiO(2) was also exhibited in the cyclic runs.
authors.affiliation: School of Environment Sciences and Engineering, Zhejiang Gongshang University, Hangzhou, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Xueshuang
authors.initials: X
authors.lastname: Chen
authors.forename: Keer
authors.initials: K
authors.lastname: Yu
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Cong
mesh_terms: D000327:Adsorption; D002384:Catalysis; D002857:Chromium / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D012235:Rhodamines / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D013472:Sunlight; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects
chemical_list: D012235:Rhodamines; D014874:Water Pollutants, Chemical; D002857:Chromium; C009495:titanium dioxide; C074702:chromium hexavalent ion; D014025:Titanium; C029773:rhodamine B