Flower-shaped S-scheme CdS-ZnO nanorods heterojunction assisted with SPR of low-content Au for accelerating photocatalytic hydrogen production

Plasmonic heterojunctions present excellent photocatalytic performance for water splitting. Herein, a novel S-scheme heterojunction of CdS-ZnO nanorods assisted with low-content Au (<1 wt%) plasmon was achieved successfully, which possessed the H2-generated efficiency of 14.36 mM h−1 g−1. Remarkable catalytic activity stems from the S-scheme mechanism, metal plasma resonance and the unique flower-shaped morphology. S-scheme endues the heterojunction with efficient carrier separation and strong redox capacity, and surface plasmon resonance (SPR) generated from low-content Au broadens light absorption range and injects hot electrons into the heterojunction. In-situ XPS measurements verified an S-scheme carrier migration mechanism as well as hot electrons transfer. Other optical and photoelectric characterizations, as well as simulation calculation by finite difference time domain (FDTD) were also utilized to conjecture the probable mechanism. Low content noble metal and unique morphology accelerate the photocatalytic H2-production, and it likely proposes the promising strategy for practical application of photocatalysis for solar energy conversion.