Photocatalytic degradation of amoxicillin using Co-doped TiO2 synthesized by reflux method and monitoring of degradation products by LC–MS/MS

Abstract

Photocatalytic degradation of Amoxicillin (AMX) in aqueous solution by Co-doped TiO2 and undoped TiO2 synthesized by reflux route was investigated. The catalysts were characterized using X-ray diffractometry, FT-IR spectroscopy, UV-Vis absorption spectroscopy, scanning electron microscopy and X-ray Fluorescence Spectroscopy, and using specific surface area, particle size and zeta potential measurements. Photocatalytic efficiency of Co-doped and undoped TiO2 was compared for degradation of AMX under UV-C and visible irradiation by investigating the effects of the parameters such as percentage of the cobalt doped, amount of catalyst, irradiation time, initial AMX concentration and pH of the medium. Effects of organic and inorganic ions in the aqueous solution were also studied. Results showed that degradation of AMX is improved by Co doping to TiO2. It was detected that complete removal is achieved within 240 min of irradiation under UV-C and 300 min under visible irradiation. 94%, 21% and 16% degradation efficiencies were achieved after 300 min of photocatalysis under visible light in the presence of Co-doped TiO2, undoped TiO2 and Degussa P25 TiO2, respectively. Degradation products were determined and followed using LC–MS/MS technique to describe the evolution of AMX. An attempt was made to estimate the photocatalytic cleavage pathway of AMX by LC-MS/MS