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 carrier and restrains the further development of these photocatalysts. Herein, a novelty SnO2/CdS 2D in-plane heterojunction is designed and fabricated, in which interfacial lattice match occurs in the nanosheets providing a reasonable condition for close combination between SnO2 and CdS. 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 carrier migrating following S-scheme mechanism. Eventually, contributed by the appropriate surface hydrogen adsorption free energy and enhanced reduction abilities of the electrons, the photocatalytic H2 production of optimized SnO2/CdS nanosheets is about 10 and 5 times higher than that of SnO2 and CdS. The excellent performance of SnO2/CdS and novel designed synthetic method provide opportunities to develop advanced photocatalysts for water splitting.