Graphical Abstract

Chemically bonded α-Fe₂O₃/Bi₄MO₈Cl (M=Nb, Ta) dot-on-plate Z-scheme junctions with strong internal electric field are crafted by an in situ growth route, which provides a powerful driving force, abundant atomic-level charge flow highways and a decreased energy barrier for directional migration and spatial separation of photocharges, greatly improving the photocatalytic activity for selective photo-oxidation of aromatic alcohols.

Abstract

Inferior contact interface and low charge transfer efficiency seriously restrict the performance of heterojunctions. Herein, chemically bonded α-Fe₂O₃/Bi₄MO₈Cl (M=Nb, Ta) dot-on-plate Z-scheme junctions with strong internal electric field are crafted by an in situ growth route. Experimental and theoretical results demonstrate that the internal electric field provides a powerful driving force for vectorial migration of photocharges between Bi₄MO₈Cl and α-Fe₂O₃, and the interfacial Fe？O bond not only serves as an atomic-level charge flow highway but also lowers the charge transfer energy barrier, thereby accelerating Z-scheme charge transfer and realizing effective spatial charge separation. Impressively, α-Fe₂O₃/Bi₄MO₈Cl manifests a significantly improved photocatalytic activity for selective oxidation of aromatic alcohols into aldehydes (Con. ≥92%, Sel. ≥96%), with a performance improvement of one to two orders of magnitude. This work presents atomic-level insight into interfacial charge flow steering.

Article link: https://doi.org/10.1002/anie.202203519