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

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 TiO2 nanotube array electrodes supported by precious metal Ag nanoparticles was investigated. The Ag/TiO2 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/TiO2 NTs. While 36 % of 2,4,6-TCP was degraded by the pure TiO2 NTs. Moreover, the density function theory (DFT) was used to explore the mechanism of the degradation of 2,4,6-TCP by center dot 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.

Automated summary

The degradation mechanism of 2,4,6-trichlorophenol (2,4,6-TCP) by photocatalysts is not well understood. This study investigated the photoelectrocatalytic degradation of 2,4,6-TCP at the solid-liquid interface using TiO2 nanotube array electrodes supported by Ag nanoparticles. The results showed that the Ag/TiO2 electrode effectively enhanced the photoelectrocatalytic activity during the degradation of 2,4,6-TCP, and proposed two sequential pathways for its degradation.