Photodecolorization of Rhodamine B on tungsten-doped TiO2/activated carbon under visible-light irradiation.
Tungsten-doped TiO(2)/activated carbon catalysts have been prepared by a supercritical-pretreatment-assisted sol-gel process. The structural features of the photocatalysts have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV/Vis diffuse-reflectance spectroscopy (DRS), electron dispersive X-ray (EDX), photoluminescence spectroscopy, and Brunauer-Emmett-Teller (BET) analysis. The results revealed that a W-TiO(2) layer was coated on the AC surface, and had higher surface area and smaller crystallite size than TiO(2)/AC obtained by a similar route. The W dopant was responsible for narrowing the band gap of TiO(2) and shifting its optical response from the ultraviolet (UV) to the visible-light region. The photocatalytic performances of the supported catalysts have been evaluated for the degradation of Rhodamine B (RhB) solution under visible-light irradiation. Compared with bulk W-TiO(2), the photoactivity was obviously enhanced when it was coated onto AC. In addition, it was found that the reactivity showed a significant relationship with the amount of W dopant, and the photoactivity order of the catalysts from weak to strong showed good agreement with their PL intensities. The effects of TiO(2) content, tungsten ion content, catalyst amount, pH, and initial RhB concentration have been examined as operational parameters. The photocatalytic reactions followed pseudo-first-order kinetics and are discussed in terms of the Langmuir-Hinshelwood model.
College of Chemistry and Chemical Engineering, Jishou University, 416000 Hunan, PR China. bcclyj@163.com
Youji
Y
Li
Xiaoming
X
Zhou
Wei
W
Chen
Leiyong
L
Li
Mengxiong
M
Zen
Shidong
S
Qin
Shuguo
S
Sun
D002244:Carbon / Q000737:chemistry / Q000528:radiation effects; D002384:Catalysis; D003116:Color; D005456:Fluorescent Dyes / Q000737:chemistry / Q000528:radiation effects*; D008027:Light; D008855:Microscopy, Electron, Scanning; D012235:Rhodamines / Q000737:chemistry / Q000528:radiation effects*; D013056:Spectrophotometry, Ultraviolet; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects*; D014414:Tungsten / Q000737:chemistry / Q000528:radiation effects*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification / Q000379:methods; D014961:X-Ray Diffraction
D005456:Fluorescent Dyes; D012235:Rhodamines; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; D002244:Carbon; D014025:Titanium; D014414:Tungsten