Photocatalytic degradation of 2,4-dichlorophenoxyacetic acid on N-doped titanium dioxide

Abstract

Photocatalytic degradation, especially hetetogeneous catalytical oxidation is an emerging method for removing organic contaminants in water. TiO₂ catalyst with excellent mechanical and thermal properties has been paid much attention. However, TiO₂ catalyst suffers from reduced photonic efficiency. In this study TiO₂ catalyst has been prepared by sol-gel method and modified in presence of urea by thermal treatment at 450 °C for 1 hour with heating rate of 5 °C/min. This catalyst was used in photocatalytic degradation of 2,4-Dichlorphenoxyacetic acid (2,4-D). The influence of reaction parameters such as radiation source, pH, 2,4-D initial concentration and catalyst content was investigated. Under UVA radiation, with 2,4D solution of 60 ppm at pH 3 and catalyst content of 0.6 g/L, the conversion was of 63 %, but under VIS radiation only about 30 %.

Keywords. TiO₂, N-doped TiO₂, 2,4-Dichlorophenoxyacetic acid, photocatalysis, UVA, VIS.