An In-Plane S-Scheme Heterostructure Drives H2 Production with Water and Solar Energy

Construction of S-scheme photocatalysts for sustainable hydrogen production has been regarded as a promising route to effectively utilize solar energy. However, the limited contact area blocks extensive migration of charge carriers and restrains the further development of these photocatalysts. Herein, a novelty S-scheme in-plane heterojunction is designed and fabricated by contacting SnO2 and CdS, in which interfacial lattice match between SnO2 and CdS ensures the tightness and stability of heterostructure. Specially, experimental results and corresponding density functional theory simulation jointly identify the charge redistribution and formation internal electric field between two branches, which is the intrinsic cause for promoting charge carriers migrating following S-scheme mechanism. Eventually, the photocatalytic H2 production of optimized SnO2/CdS nanosheets is about 10 and 5 times higher than that of SnO2 and CdS contributed by the appropriate surface hydrogen adsorption free energy and enhanced reduction abilities of the electrons in this S-scheme system. This work provides a valuable guide in rationally synthesizing nanocomposite for efficient photocatalytic water splitting