Enhanced Photoelectrocatalytic Activity of a Novel Bi2O3-BiPO4 Composite Electrode for the Degradation of Refractory Pollutants under Visible Light Irradiation

A novel Bi2O3-BiPO4 composite electrode was successfully synthesized by the method of electrophoretic deposition, electrodeposition, and calcination in a proper sequence. The prepared electrodes were characterized by X-ray diffractometry (XRD) and scanning electronic microscopy (SEM). Linear sweep voltammetry (LSV) and photocurrent decay curves measurement indicated that the Bi2O3-BiPO4 composite electrode exhibited better photoelectrochemical (PEC) activity than either pure Bi2O3 or BiPO4 electrode. Incident photon to current conversion efficiency (IPCE) and electrochemical impedance spectra (EIS) measurements revealed that the composite electrode significantly improved the efficiency of charge transfer and decreased the recombination of photogenerated charges. Furthermore, the composite electrode also displayed higher efficiency and stability in the PEC degradation of organic pollutants. The p-n junction structure of the Bi2O3-BiPO4 composite electrode was most likely responsible for the enhanced PEC activity.