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.