Cu7S4/MxSy (M=Cd, Ni, and Mn) Janus Atomic Junctions for Plasmonic Energy Upconversion Boosted Multi‐Functional Photocatalysis

Abstract

AbstractRational design/synthesis of atomic‐level‐engineered Janus junctions for sunlight‐impelled high‐performance photocatalytic generation of clean fuels (e.g., H2O2 and H2) and valuable chemicals are of great significance. Especially, it is appealing but challenging to acquire accurately‐engineered Janus atomic junctions (JAJs) for simultaneously realizing the plasmonic energy upconversion with near‐infrared (NIR) light and direct Z‐scheme charge transfer with visible light. Here, a range of new Cu7S4/MxSy (M=Cd, Ni, and Mn) JAJs are designed/synthesized via a cation‐exchange route using Cu7S4 hexagonal nanodisks as templates. All Cu7S4/MxSy JAJs show apparently‐enhanced photocatalytic H2O2 evolution compared to Cu7S4 in pure water. Notably, optimized Cu7S4/CdS (CCS) JAJ exhibits the outstanding H2O2 evolution rate (2.93 mmol g−1 h−1) in benzyl alcohol aqueous solution, due to the following factors: i) NIR light‐impelled plasmonic energy upconversion induced H2O2 evolution, revealed by ultrafast transient absorption spectroscopy; ii) visible‐light‐driven direct Z‐scheme charge migration, confirmed by in situ X‐ray photoelectron spectroscopy. Besides, three different reaction pathways for H2O2 evolution are disclosed by in situ electron spin resonance spectroscopy and quenching experiments. Finally, CCS JAJ also exhibits super‐high rates on H2 and benzaldehyde co‐generation using visible‐NIR light or NIR light. This work highlights the significance of atomic‐scale interface engineering for solar‐to‐chemical conversion.