The Visible-Light Photocatalytic Activity and Antibacterial Performance of Ag/AgBr/TiO2 Immobilized on Activated Carbon

• Published in: Photochemistry and photobiology Vol. 92; no. 6; pp. 800 - 807
• Main Authors: Yang, Lu, Ye, Fangyun, Liu, Peng, Wang, Fazhou
• Format: Journal Article
• Language: English
• Published: Lawrence Blackwell Publishing Ltd 01.11.2016
• Subjects: Activated carbon; Light; Photocatalysis
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1111/php.12653

Visible‐light‐driven Ag/AgBr/TiO2/activated carbon (AC) composite was prepared by solgel method coupled with photoreduction method. For comparison, TiO2, TiO2/AC, and Ag/AgBr/TiO2 were also synthesized. Their characteristics were analyzed by XRD, SEM‐EDS, TG‐DSC and UV–vis techniques. Photocatalytic activity and antibacterial performance under visible‐light irradiation were investigated by ICP‐AES, ATR‐FT‐IR and spectrophotometry methods using methylene blue and Escherichia coli as target systems, respectively. The results showed that Ag/AgBr was successfully deposited on anatase TiO2/AC surface, and exhibited a distinct light absorption in the visible region. Ag/AgBr/TiO2/AC displayed excellent antibacterial performance both in dark and under visible‐light illumination. The growth of E. coli cell was inhibited in the presence of Ag/AgBr/TiO2/AC in dark. Moreover, upon visible‐light illumination, a significant damage of cell membrane was noticed. Ag/AgBr/TiO2/AC was also shown higher photocatalytic efficiency for methylene blue degradation than those of TiO2, TiO2/AC, and Ag/AgBr/TiO2. This is attributed to the synergetic effect between AC and Ag/AgBr/TiO2, of which AC acts as the role of increasing reaction areas, continuous enriching, and transferring the adsorbed MB molecules to the surface of supported photocatalysts, and the Ag/AgBr/TiO2 acts as a highly active photocatalyst for degrading MB molecules under visible‐light irradiation. The highest photocatalytic efficiency of Ag/AgBr/TiO2/AC for degradating MB and E. coli is attributed to the dynamic adsorption‐ high photocatalysis process under visible light irradiation, where AC acts as the role of increasing reaction areas, continuous enriching and transferring the adsorbed target molecules to the supported photocatalysts, and for degrading target molecules, the Ag/AgBr/TiO2 acts as a high activity photocatalyst through forming the abundant free radical species under visible light irradiation.