The Photocatalytic Performance of JANUS SXSiN₂ (X = Cr, Mo, W) Monolayers with Enhanced Carrier Migration

Efficient catalysts for separating electron–hole pairs are crucial for improving the quantum yield and activity of photocatalysts. This study systematically investigates the properties and performance of monolayers of Janus SXSiN₂ (X = Cr, Mo, W) using the first-principles computational methods. The research findings suggest that biaxial strain can induce an indirect-to-direct bandgap transition in Janus SXSiN₂ and can also modulate the bandgap and band edge positions. Surface vacancy defects play a critical role in enhancing the charge carrier separation ability of Janus SXSiN₂, leading to remarkable photocatalytic performance. Moreover, the synergistic effect of biaxial strain and vacancy defects can significantly improve the catalytic performance for the HER. This study provides a theoretical foundation for further development of efficient two-dimensional Janus photocatalysts.