Experimental and quantum chemical investigation on the mechanism of photocatalytic degradation of 2,4,6-trichlorophenol by Ag/TiO2 nanotube electrode

Abstract

• Ag/TiO2 NTs was obtained by simple anodization and photocatalytic reduction method. • The intermediate products were identified by DFT calculations and experiment. • Two sequential pathways leading to degradation of 2,4,6-TCP was proposed. 2,4,6-Trichlorophenol (2,4,6-TCP) can be degraded by photocatalysts efficiently. However, the degradation mechanism of the 2,4,6-TCP has not clear enough. The photoelectrocatalytic degradation of 2,4,6-TCP at the solid–liquid interface by TiO 2 nanotube array electrodes supported by precious metal Ag nanoparticles was investigated. The Ag/TiO 2 electrode improve the photoelectrocatalytic activity effectively during the degradation of 2,4,6-TCP. The 100 % removal of 2,4,6-TCP was observed after 120 min by the Ag/TiO 2 NTs. While 36 % of 2,4,6-TCP was degraded by the pure TiO 2 NTs. Moreover, the density function theory (DFT) was used to explore the mechanism of the degradation of 2,4,6-TCP by OH. The intermediate products were identified by DFT calculations and experiment. According to the identified intermediate product, two sequential pathways leading to degradation of 2,4,6-TCP was proposed. This study provides an effective way for probing the degradation mechanism of 2,4,6-TCP.