Constructing N-Cu-S Interface Chemical Bonds over SnS2 for Efficient Solar-Driven Photoelectrochemical Water Splitting

The restricted charge transfer and slow oxygen evolution reaction (OER) dynamics tremendously hamper the realistic implementation of SnS2 photoanodes for photoelectrochemical (PEC) water splitting. Here, a novel strategy is developed to construct interfacial N-Cu-S bonds between N-C skeletons and SnS2 (Cu-N-C@SnS2) for efficient PEC water splitting. Compared with SnS2, the PEC activity of Cu-N-C@SnS2 photoelectrode is tremendously heightened, obtaining a current density of 3.40 mA cm(2) at 1.23 V-RHE with a negatively shifted onset potential of 0.04 V-RHE, which is 6.54 times higher than that of SnS2. The detailed experimental characterizations and theoretical calculation demonstrate that the interfacial N-Cu-S bonds enhance the OER kinetic, reduce the surface overpotential, facilitate the separation of photon-generated carriers, and provide a fast transmission channel for electrons. This work presents a new approach for modulating charge transfer by interfacial bond design in heterojunction photoelectrodes toward promoting PEC performance and solar energy application.

Automated summary

In this study, a novel strategy is developed to construct interfacial N-Cu-S bonds for efficient photoelectrochemical water splitting on SnS2 photoelectrodes. The results show that the interfacial bonds enhance oxygen evolution reaction kinetics, reduce surface overpotential, facilitate carrier separation, and provide a fast transmission channel for electrons.