In Situ Observation of Single Au Triangular Nanoprism Etching to Various Shapes for Plasmonic Photocatalytic Hydrogen Generation.

In situ etching of single Au triangular nanoprism (TNP) was successfully monitored by the plasmonic photoluminescence (PL) spectra using single-particle microscopy, which provides clear results to understand the geometric and anisotropic dependence of surface plasmon resonance in Au nanostructures. Various Au nanostructures (TNP, obtuse TNP (O-TNP) and nanodisk) were obtained to synthesize anisotropic Pt-Au as plasmonic photocatalyts for hydrogen generation. Single-particle PL spectra and finite-difference time-domain simulations demonstrate that the Pt-edged Au O-TNP has larger tip area and higher plasmon enhanced electrical field for hot electron transfer and charge separation, leading to more efficient photocatalytic hydrogen generation.