Efficient removal of bisphenol A and Cr(VI) simultaneously in an advanced redox photoelectrocatalytic system over dual 3D TiO2 photoelectrodes

An adventurous strategy on the premise of synergistic photoelectrocatalysis (PEC) system based on three-dimensional (3D) TiO2 is proposed to realize the simultaneous removal of BPA and Cr(VI). The TiO2 photoelectrode demonstrates a 3D configuration, meanwhile supplies a multilevel facet heterojunction (FH). The dual-FH-TiO2/Ti PEC system is constructed via the application of 3D FH-TiO2/Ti as both cathode and anode, where the redox efficiency of BPA and Cr(VI) increased by 1.07 and 4.28 times of the single system. The visible growth accounts for more exposure of active sites and a higher utilization of active species, proved by EPR and quenching experiments. In the practical wastewater, the removal efficiency of BPA and Cr(VI) reaches 97.04% and 81.18% in 1 h. The effects of various influence factors such as pH, electrolyte concentration and coexisting ions on BPA and Cr(VI) removal are studied for practical applications.