Au–Ag alloy nanoparticle-incorporated AgBr plasmonic photocatalyst

Abstract

A solid-phase photochemical method produces Au–Ag alloy nanoparticles (NPs) with a sharp size distribution and varying composition in AgBr crystals (Au–Ag@AgBr). These features render Au–Ag@AgBr promising as a material for the plasmonic photocatalyst further to provide a possibility of elucidating the action mechanism due to the optical tunability. This study shows that the visible-light activity of Au–Ag@AgBr for degradation of model water pollutant is very sensitive to the alloy composition with a maximum at the mole percent of Au to all Ag in AgBr (y) = 0.012 mol%. Clear positive correlation is observed between the photocatalytic activity and the quality factor defined as the ratio of the peak energy to the full width at half maximum of the localized surface plasmon resonance band. This finding indicates that Au–Ag@AgBr works as a local electromagnetic field enhancement-type plasmonic photocatalyst in which the Au–Ag NPs mainly promotes the charge separation. This conclusion was further supported by the kinetic analysis of the light intensity-dependence of external quantum yield.

A review on plasmonic-based heterojunction photocatalysts for degradation of organic pollutants in wastewater

“…Recently, plasmonic-based heterojunction photocatalysts have attracted enormous attention for organic pollutants degradation [ 61 , 201 , 202 ]. This is due to the remarkable properties of plasmonic-based heterojunction photocatalysts such as (1) effective separation and transfer of photogenerated e − – h + , (2) improvement of stability, and (3) enhancement of light absorption of the photocatalyst [ 92 , 203 ]. Moreover, LSPR in plasmonic metal NPs is beneficial to the performance of photocatalytic processes in many ways.…”