Plasmonic Au nanoparticle-decorated Bi₂Se₃ nanoflowers with outstanding electrocatalytic performance for hydrogen evolution

Hydrogen production from water splitting through electrocatalytic or photoelectrochemical route shows great potential for renewable energy conversion. Herein, the plasmon-enhanced photoelectrical nanocatalysts (NCs) have been successfully developed by Au nanoparticle-decorated Bi₂Se₃ nanoflowers (Au@Bi₂Se₃ NFs) as catalysts for hydrogen evolution reaction (HER), leading to a more than 3-fold increase of current under excitation of Au localized surface plasmon resonance (LSPR) and affording a markedly decreased overpotential of 375 mV at a current density of 10 mA cm⁻². The HER enhancement can be largely attributed to effective electron-charge separation and the increase of carrier density in Bi₂Se₃ induced by the injection of hot electrons of Au nanoparticles. Meanwhile, Bi₂Se₃ nanoflowers (NFs), a kind of topological insulators, possess gapless edges on boundary and show metallic character on surface, providing a path for the flow of electrons in the electrocatalytic system. This study opens up a new avenue towards the design of higher energy conversion catalytic water splitting systems with the assistance of light energy, which could increase of HER catalysis efficiency by plasmonic excitation.