LAUSR

Abstract BiVO4 has attracted great attention as a semiconductor for Photoelectrochemical (PEC) water splitting because of its low cost, good stability, and suitable band gap of 2.4 eV. In this research, the contribution of g-C3N4@ZnO on BiVO4 photoelectrochemical performance, light absorption, charge transportation, and morphology were investigated. Incorporation of g-C3N4/ZnO as underlying layer in heterojunction with BiVO4 boosted the photocurrent from ∼ 0.21 mA cm−2 for bare BiVO4 to 0.65 mA cm−2 for g-C3N4@ZnO/BiVO4 heterojunction composite structure at 1.23 V versus Ag/AgCl. The C and N elements derived from g-C3N4 on ZnO resulted in a tenacious interactions, lowered charge transfer resistance and increased light absorption of BiVO4. The high photoelectrochemical performance, together with good electrochemical impedance spectroscopy parameters and stability reveals g-C3N4/ZnO composite to be a suitable candidate in enhancing the performance of BiVO4 for PEC solar water splitting applications.