Graphene oxide-grafted plasmonic Au@Ag nanoalloys with improved synergistic effects for promoting hot carrier-driven photocatalysis under visible light irradiation.

Plasmonic metallic nanostructure with unique hot carrier-driven photocatalysis has recently emerged as a promising photocatalyst. Herein, we show that the plasmonic photocatalysis can be significantly promoted by supporting bimetallic Au@Ag nanoalloys (NAs) on graphene oxide (GO). The obtained Au3@Ag1/GO (molar ratio of Au to Ag~3:1) with improved synergistic effects provides a remarkable higher visible-light (>400nm) photocatalytic activity for a complete degradation (99.36%) of tetracycline hydrochloride (TCH) molecules within 70 min, while about 61.74% or 62.38% via monometallic Au/GO or Ag/GO. The optimum photocatalytic performance is attributed to the production of high yield hot carriers on NAs with enhanced localized surface plasmon resonance (LSPR) property and the pronounced photoinduced electron-transfer ability of modified GO support by overgrowth of NAs. These findings enable the optimal Au3@Ag1/GO to become an appealing high-performance photocatalyst for promoting diverse photochemical reactions.