Synergy of Facet and Defect on Carrier Dynamics of Photocatalyst Particles.

Zhang, Tingbo; Ji, Qun; Chen, Qian; Ju, Ming-Gang; Wang, Jinlan · Nano Lett · 2025

basic_science · Level V

Where this comes from

Abstract

Cu<sub>2</sub>O semiconductors are highly regarded in photocatalysis for their outstanding photogenerated carrier dynamics. However, the mechanisms underlying carrier separation and recombination in Cu<sub>2</sub>O remain elusive, largely due to the intricate interplay between defects and facet engineering. Herein, we elucidate the critical synergy between internal defects and facets in Cu<sub>2</sub>O for carrier dynamics. Specifically, split Cu vacancy and H interstitial defects preferentially capture holes and electrons, respectively, leading to effective separation of photogenerated carriers in the different Cu<sub>2</sub>O facets. Moreover, H interstitials can also convert split Cu vacancies into H-filled Cu vacancies, eliminating midgap states and extending the photogenerated carrier lifetime of Cu<sub>2</sub>O. The efficient separation and extended lifetime of carrier enhances the photocatalytic efficiency of Cu<sub>2</sub>O. Our findings reveal the defect-dependent mechanism for photogenerated carrier dynamics in photocatalysts with different facets, offering valuable insights for facet regulation in high-performance photocatalysis.