Selective imines synthesis by designing an atomic-level Cu–Pt electron transfer channel over CdS nanosheets

The precise design of the charge carrier relay channel and active sites of semiconductor-based photocatalysts is highly crucial for target selective photoredox synthesis. In this context, we report an atomic-level catalyst design strategy based on depositing Pt single atoms (SAs) onto Cu-doped ultrathin cadmium sulfide nanosheets (CdS/Cu/Pt) to enable an optimized band structure, a directional charge transfer channel, and favorable catalytic sites for efficient and selective dehydrocoupling of amines to imines and hydrogen (H2). The Cu dopant acts as a unique electron bridge to construct a directional Cu-Pt electron transfer channel with the assistance of atomically dispersed Pt sites, thereby promoting charge separation and transfer kinetics. The introduction of Pt SAs not only facilitates the H2 generation by decreasing the overpotential of proton reduction but also improves the selectivity of imines synthesis because the weak adsorption of imines on Pt SAs prevents further hydrogenation of imines to secondary amines. This work is anticipated to inspire a further rational design of semiconductor-based photocatalysts with atomic precision for the coproduction of renewable fuels and value-added fine chemicals.