TY - JOUR
T1 - Bimodal N-doped P25-TiO 2/AC composite
T2 - Preparation, characterization, physical stability, and synergistic adsorptive-solar photocatalytic removal of sulfamethazine
AU - Yap, Pow Seng
AU - Cheah, Yan Ling
AU - Srinivasan, Madhavi
AU - Lim, Teik Thye
N1 - Funding Information:
The financial support provided by the National Research Foundation (NRF), Singapore through project EWI RFP 0802-11 is gratefully acknowledged. P.-S. Yap thanks Nanyang Technological University (NTU) for the award of a PhD research scholarship.
PY - 2012/6/15
Y1 - 2012/6/15
N2 - A novel nitrogen-doped P25-TiO 2 of bimodal structure with activated carbon supported (N-P25-TiO 2/AC) was synthesized via the modified sol-gel techniques. Besides adding urea as N-source, the N-doping could also be induced through calcination under mixed NH 3/N 2 atmosphere. The composite was characterized using XRD, porosimetry, UV-vis spectrophotometry, FTIR, XPS, SEM/EDX and TEM. The physical stability of the composite was examined through ultrasonication disruption, and the composite exhibited good physical stability. The synergistic effects of the adsorption-solar photocatalysis of sulfamethazine (SMZ) as exhibited by the composites were examined. The best performing bimodal composite was N-P25-TiO 2 (25 + 10)/AC, which comprised 25% of N-P25 and 10% N-TiO 2 (sol) by weight composition (wt%). The maximum adsorption capacity (S max) for the N-P25-TiO 2 (25 + 10)/AC, at pH 3.0, 6.0 and 10.0 was 183 ± 3, 194 ± 3, and 103 ± 2 mg g -1, respectively. The effects of the total loading of N-doped titania, sol-gel synthesis technique, weight distribution of N-P25 and N-TiO 2 (sol), composite dosage, light wavelength spectrum and solution pH on the photocatalytic degradation (PCD) of SMZ were investigated. The N-P25-TiO 2 (25 + 10)/AC composite exhibited enhanced PCD efficiency under solar irradiation with a pseudo first-order rate constant (k app) of 0.48 h -1, as compared to other types of bimodal composites because its higher N-P25 content led to a greater photocatalytic activity.
AB - A novel nitrogen-doped P25-TiO 2 of bimodal structure with activated carbon supported (N-P25-TiO 2/AC) was synthesized via the modified sol-gel techniques. Besides adding urea as N-source, the N-doping could also be induced through calcination under mixed NH 3/N 2 atmosphere. The composite was characterized using XRD, porosimetry, UV-vis spectrophotometry, FTIR, XPS, SEM/EDX and TEM. The physical stability of the composite was examined through ultrasonication disruption, and the composite exhibited good physical stability. The synergistic effects of the adsorption-solar photocatalysis of sulfamethazine (SMZ) as exhibited by the composites were examined. The best performing bimodal composite was N-P25-TiO 2 (25 + 10)/AC, which comprised 25% of N-P25 and 10% N-TiO 2 (sol) by weight composition (wt%). The maximum adsorption capacity (S max) for the N-P25-TiO 2 (25 + 10)/AC, at pH 3.0, 6.0 and 10.0 was 183 ± 3, 194 ± 3, and 103 ± 2 mg g -1, respectively. The effects of the total loading of N-doped titania, sol-gel synthesis technique, weight distribution of N-P25 and N-TiO 2 (sol), composite dosage, light wavelength spectrum and solution pH on the photocatalytic degradation (PCD) of SMZ were investigated. The N-P25-TiO 2 (25 + 10)/AC composite exhibited enhanced PCD efficiency under solar irradiation with a pseudo first-order rate constant (k app) of 0.48 h -1, as compared to other types of bimodal composites because its higher N-P25 content led to a greater photocatalytic activity.
KW - Activated carbon
KW - Bimodal titania
KW - Physical stability
KW - Solar photocatalysis
KW - Sulfamethazine
UR - http://www.scopus.com/inward/record.url?scp=84860507400&partnerID=8YFLogxK
U2 - 10.1016/j.apcata.2012.03.042
DO - 10.1016/j.apcata.2012.03.042
M3 - Article
AN - SCOPUS:84860507400
SN - 0926-860X
VL - 427-428
SP - 125
EP - 136
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -