Band-potential fluctuation in C3N4/BiOCl hetero-junction for boosting photo-catalytic activity

Abstract Designing hetero-junction photo-catalysts with high separation efficiency of photo-generated charge carriers has been recognized as an optimistic route to water purification and hydrogen generation. The interfacial interaction and band-potential fluctuation in forming hetero-junction play important roles in photo-catalytic activity. In this work, a series of highly active layer-structured g-C3N4/BiOCl (C3N4/BOC) hetero-junction have been successfully synthesized through a two-step calcination-hydrothermal method. The hetero-junction photo-catalysts exhibit 8.15 times higher degradation rate for Rhodamine B (RhB) and 6.97 times higher H2 evolution rate than those of pristine g-C3N4. For comprehensively understand the charge transfer mechanism, experimental characterization and theoretical Density functional theory (DFT) calculations are adopted in the single-phase semiconductor and hetero-junction system. The superior photo-induced electron-holes separation ability and band-potential fluctuation of present photo-catalysts are confirmed. This work provides insightful understanding for the formation mechanism of hetero-junction photo-catalysts.