Construction of Highly Efficient Photocatalyst with Core‐Shell Au@Ag/C@SiO2 Hybrid Structure towards Visible‐Light‐Driven Photocatalytic Reduction

Abstract

Main observation and conclusionHerein, we report a rational construction of Au@Ag/C@SiO2 system with Au@Ag core‐shell nanoparticles (NPs) as a promising photocatalyst based on the plasmonic coupling effect for the first time towards the photoreduction of nitroaromatic compounds under visible light. The combination and elaborate construction of Au@Ag NPs, carbon microspheres and mesoporous SiO2 shell can endow this system with several outstanding features towards photocatalytic reaction. Firstly, the broadband light harvesting across ultraviolet‐visible‐near infrared (UV‐vis‐NIR) region can be achieved due to the comprehensive effect of surface plasmonic resonance (SPR) coupling model of Au and Ag, near‐field scattering light of carbon microspheres and light reflecting effect of SiO2 shell, resulting in the production of more electrons for phororeduction reaction. Secondly, the carbon microspheres in Au@Ag/C@SiO2 system possess electron‐rich property due to their strong electron‐withdrawing ability, which can act as the Lewis acid and Lewis basic site, and promote the stepwise hydrogenation of nitrobenzene. Thirdly, Au@Ag/C@SiO2 exhibits excellent reusability because of the protection of SiO2 shell, which restricts metal NPs inside the spheres and protects them from aggregation and being lost during reaction process. Our present work demonstrates the significance of construction of hybrid nanostructures based on the plasmonic coupling effect, which can be a promising approach to design efficient photocatalyst towards organic synthesis under visible light.