Efficient photodegradation of Acid Red B by immobilized ferrocene in the presence of UVA and H2O2.
SiO2-C2H4-ferrocene (SiCFe) was synthesized by covalent grafting of ferrocene on functionalized silica gel with a -C2H4- linkage. On the basis of characterization by diffuse reflectance UV-vis spectra (DRS) and Fourier transform infrared spectra (FT-IR), ferrocene has been successfully anchored on the silica gel. Under UVA (lambdamax=365 nm) irradiation, the catalyst exhibited high photocatalytic activity in the degradation of Acid Red B (ARB), especially in the presence of H2O2. Meanwhile, the catalytic activity of SiCFe was maintained effectively even after reused for 4 times without any significant destruction of ferrocene. The influence of initial solution pH and wavelength of UV light on the catalyst's activity was also investigated. Electron spin resonance (ESR) studies revealed that both OH and HO2/O2- radicals were involved as the active species in the ARB degradation process. Furthermore, results of total organic carbon (TOC) and FT-IR analysis indicated that ARB degradation proceeded by the cleavage of NN, followed by hydroxylation and opening of phenyl rings to form aliphatic acids and further oxidization of the aliphatic acids to produce carbon dioxide and water. A possible reaction mechanism was proposed on the basis of all the information obtained under various experimental conditions.
Nie
Yulun
Y
State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Hu
Chun
C
Qu
Jiuhui
J
Hu
Xuexiang
X
D001391:Azo Compounds / Q000737:chemistry / Q000528:radiation effects; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry / Q000528:radiation effects; D005296:Ferrous Compounds / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D000075163:Metallocenes; D009282:Naphthalenesulfonates / Q000737:chemistry / Q000528:radiation effects; D010777:Photochemistry; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
D001391:Azo Compounds; D004396:Coloring Agents; D005296:Ferrous Compounds; D000075163:Metallocenes; D009282:Naphthalenesulfonates; D014874:Water Pollutants, Chemical; C521611:acid red B; D058428:Silica Gel; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide; C004998:ferrocene