Hydrothermal deposition of AgCl/AgBr co-sensitizers to modify TiO2 NTs for enhanced photocatalytic performance

Abstract

AgCl/AgBr co-sensitizers were prepared on TiO2 nanotube arrays (TiO2 NTs/AgCl/AgBr) by the hydrothermal method. The composition, morphology, optical absorption, photoelectric and photoelectrocatalytic (PEC) performances of TiO2 NTs/AgCl/AgBr were influenced by the concentration ratio of KCl/KBr. The investigation results revealed that the TiO2 NTs/AgCl/AgBr photocatalyst exhibited dramatically strong visible light absorption and outstanding photoelectrochemical capacity. The photoelectrode produced high visible light surface photovoltage (-0.43 V), transient photocurrent (0.47 mA/cm2) and carrier concentration (4.39 × 1020 cm-3). The sample also showed high PEC activity in the organic dye and Cr(VI) removal, and the photocatalytic mechanism and charge carrier transfer path were described based on PEC results. The investigation would offer prospective insight to the sensitization of TiO2 NTs, which would result in extensive attraction in the preparation and application of semiconductor materials as photoelectrodes and photocatalysts with superior photoelectrochemical performances.