Electrodeposition of Cu2O/g-C3N4 heterojunction film on an FTO substrate for enhancing visible light photoelectrochemical water splitting

Abstract

An immobilized Cu2O/g-C3N4 heterojunction film was successfully made on an FTO substrate by electrophoretic deposition of g-C3N4 on a Cu2O thin film. The photoelectrochemical (PEC) performance for water splitting by the Cu2O/g-C3N4 film was better than pure g-C3N4 and pure Cu2O film. Under –0.4 V external bias and visible light irradiation, the photocurrent density and PEC hydrogen evolution efficiency of the optimized Cu2O/g-C3N4 film was –1.38 mA/cm2 and 0.48 mL h−1 cm−2, respectively. The enhanced PEC performance of Cu2O/g-C3N4 was attributed to the synergistic effect of light coupling and a matching energy band structure between g-C3N4 and Cu2O as well as the external bias.