In-situ Ag SPR assisted S-scheme ZnO-CdS multi-layer core-shell heterojunction for enhanced photocatalytic degradation: Energy band engineering and reactive dynamics

Abstract

Constructing an efficient photocatalyst to accelerate charge separation with strong redox capacity is in pursuit all the way. Herein, a novel heterojunction was achieved for efficient organic degradation, which took advantages of S-scheme mechanism, metal surface plasma resonance (SPR) and unique morphology. The multi-layer core-shell structure can be regulated by aging time with template-free, and Ag nanoparticles were modified on the heterojunction by photochemical deposition in situ to facilitate electron transport and improve stability. S-scheme and SPR endues the heterojunction with broad light absorption, increased light utilization, efficient carrier separation, and strong redox capacity. An examination of reactive dynamics revealed that superoxide radicals and hydroxyl radicals are crucial for oxidative degradation. Introducing oxygen during the reaction process has been found to enhance the efficiency by 7 %. This article furnishes novel insights into a coordination of energy band engineering, structure regulation, as well as reaction process adjustment for facilitating photo-degradation reactions.