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

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.