Plasmonic photocatalysis: A boosting hot-electron-hole separation driven by interfacial contact potential enables high photocatalytic activity on Au_core-Ag_shell bimetallic nanoparticles towards the four-electron reduction of 4-NTP to 4,4′-DMAB.

Abstract

Plasmonic photocatalysis under visible-light irradiation has long been regarded as a very promising strategy for inducing chemical transformations. However, the efficient utilization of these hot electrons on monometallic nanoparticles to induce chemical reaction remains a challenging subject. Here, we study plasmonic hot electron activity of Au_core-Ag_shell bimetallic nanoparticles towards the four-electron reduction of 4-nitrothiophenol to 4,4′-dimercaptoazobenzene. Our results show that Au_core-Ag_shell nanoparticles possess a higher catalytic activity than pure Au and Ag nanoparticles and the photocatalytic transformation is strongly dependent on the thickness of Ag shell. The plasmonic catalytic activity could be explained by a boosting hot-electron-hole separation driven by the contact potential at the bimetallic interface. This work provides new opportunities to enhance the efficient utilization of hot electron for plasmonic photocatalysis reaction.