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

Abstract

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 cm2 at 1.23 VRHE with a negatively shifted onset potential of 0.04 VRHE , 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.