Sharing N atoms boosting Z-scheme charge transfer in SrTiO2N/CNx heterojunctions for selective photoreduction of CO2 to CH4

Abstract

Exploring charge transfer channels in the Z-scheme heterojunction is an essential challenge. A strategy to precisely connect g-C₃N₄ with SrTiO₃ through sharing N atoms was developed to create a chemically bonded Z-scheme heterojunction photocatalyst (STON/CNx). By sharing the N atoms, not only was the activity of the photocatalytic reduction of CO₂ greatly improved, but the selectivity of the product was also changed. The CH₄ product rate over optimal STON/CNx was 102.4 μmol g⁻¹ h⁻¹, with a 98.9% product selectivity. Both characterization and theoretical calculations indicate that N atoms tightly connect the heterostructures and serve as a channel for electron transport, facilitating the transfer of photogenerated electrons. This research lays a way for creating a sharing atoms’ Z-scheme interface, providing the potential for exciting future photocatalytic applications.