The Role of Interfacial Morphology in Cu2O/TiO2 and Band Bending: Insights from Density Functional Theory

Abstract: Photocatalysis, a promising solution for environmental challenges, relies on the generation and utilization of photogenerated charge carriers within photocatalysts. However, recombination of these carriers often limits efficiency. Heterostructures, especially Cu2O/TiO2, have emerged as effective solutions to enhance charge separation. This study systematically explores the effect of interfacial morphologies on the band bending within Cu2O/TiO2 anatase heterostructures, employing density functional theory (DFT). Through this study, eight distinct interfaces are identified and analyzed, revealing a consistent staggered-type band alignment. Despite variations in band edge positions, a systematic charge transfer from Cu2O to TiO2 is observed across all interfaces. The proposed band bending configurations would suggest enhanced charge separation and photocatalytic activity under ultraviolet illumination due to a Z-scheme configuration. This theoretical investigation provides valuable insights into the interplay between interfacial morphology, band bending, and charge transfer, for advancing the understanding of fundamental electronic mechanisms in heterostructures.