Enhanced visible light photoelectrocatalytic degradation of organic contaminants by F and Sn co-doped TiO2 photoelectrode

Abstract

The photoelectrocatalytic (PEC) technology has received considerable attention in the degradation of organic pollutants for its high degradation efficiency and cost effectiveness. In this study, we developed a PEC method with F and Sn co-doped TiO2 (FTS) as photoelectrodes, exhibiting an excellent PEC performance in degradation of phenol and landfill leachate under visible light irradiation and low-bias voltage. The enhanced PEC performance was mainly ascribed to the creation of a great amount of active species (such as h+ and OH) by F and Sn co-doping. The h+ and OH played a dominant role, and the roles of which were not significantly affected by Sn doping in the PEC process. The PEC degradation mechanism of phenol was further investigated by the Langmuir-Hinshelwood kinetic model and the addition of scavengers. The results indicated that the h+-created OH were mainly generated from the adsorbed OH−, and phenol was mainly degraded in the state of the ionization (C6H5O−) by the active species (h+ and OH). Furthermore, the degradation pathway of phenol was proposed according to intermediates in the PEC process.