Surface modification of porous ZnO sheets with Ag and Ag2O nanoparticles for enhanced photoelectrochemical and photocatalytic performance

Abstract

This study demonstrates significant enhancements in the structural, optical, and photoelectrochemical (PEC) properties of porous ZnO sheet templates via surface modification with metallic silver (Ag) and Ag2O nano-particles. Increased sputtering duration boosts nanoparticle coverage, gradually reducing ZnO's visible porosity. X-ray photoelectron spectroscopy confirms the presence of Ag and silver ions (Ag+), while surface plasmon resonance (SPR) effects and p-n junctions enhance light absorption and charge separation. Optical and PEC analyses identify ZA150 and ZAO130 as optimally modified samples, achieving improved light harvesting and charge dynamics. ZA150 excels in Rhodamine B degradation due to efficient SPR-assisted charge transfer, while ZAO130 benefits from built-in electric fields at the ZnO/Ag2O junction. Reactive species trapping highlights hydroxyl and superoxide radicals as the main degradation agents. Overall, the findings underscore the promise of Ag-and Ag2O-decorated ZnO in solar-driven photocatalysis and offer guidance for tuning surface characteristics to maximize efficiency.