Enhancement of Ti3C2 MXene on Au@Ag/TiO2 for the visible-light-driven photoreduction of nitroaromatics

Abstract

The hot electrons produced by the surface plasmon resonance (SPR) effect of plasmonic metals offer an efficient and sustainable strategy for traditional catalysis. However, the low generation rate and easy recombination property of hot carriers limit their application in plasmonic reactions. In this paper, Au@Ag nanoparticles are first constructed result from SPR coupling effect of the Au and Ag components, then they are further assembled on TiO₂ microspheres to form Au@Ag/TiO₂, in which the Au@Ag assemblies produce a strong SPR effect caused by the collective plasmonic excitation originating from the formation of hot spots between neighboring NPs. All of these endow Au@Ag/TiO₂ with efficient hot electron generation capability. Furthermore, Au@Ag/TiO₂ was modified by Ti₃C₂ to prepare the Au@Ag/TiO₂/Ti₃C₂ photocatalyst in consideration of the excellent electron conduction ability of the MXene. As a result, Au@Ag/TiO₂/Ti₃C₂ possesses efficient hot carrier production and separation abilities at the same time, which exhibits outstanding photocatalytic activity in the photoreduction of nitrobenzene to aniline. Under visible light, 100% conversion and aniline selectivity are achieved in 5 min at 0 °C. Moreover, Au@Ag/TiO₂/Ti₃C₂ displays excellent reusability.