Dynamic Electron-Hole Shuttle at Atomic Interfaces for Solar-Driven H₂O₂ and Benzaldehyde Coproduction.

Abstract

Harnessing solar energy to produce value-added chemicals simultaneously requires the critical step of spatially separating redox processes. However, conventional photocatalysts remain fundamentally constrained by sluggish charge dynamics and irreversible recombination. Here, we propose an atomic-level interfacial shuttle mechanism in sub-nanometer gold cluster-anchored nickel manganite (H-NiMn₂O_4-β/Au_0.5 NCs), which couples dynamic electron-hole separation with Ni³⁺/Ni²⁺ redox cycling. Ultrafast transient absorption spectroscopy indicates electron transfer occurring within 3.06 ps, mediated by an Au-O-Ni coordination interface. In this system, Ni³⁺ functions as a transient electron trap, undergoing rapid reduction to Ni²⁺ and subsequently transferring electrons to adjacent Au clusters, accelerating charge kinetics by 22.16-fold. This atomic-scale electron relay selectively steers 2e^- oxygen reduction by balancing *OOH intermediate stabilization and desorption, yielding H₂O₂ at 1.00 mmol g^-1 h^-1. Simultaneously, hole accumulation on lattice oxygen drives α-H abstraction, enabling photooxidation of benzyl alcohol to benzaldehyde (14.59 mmol g^-1 h^-1). This work presents a dynamic dual-site catalysis model, offering atomic-level insight into interfacial charge management for solar-driven redox transformations.