Plasmonic Pd nanoparticles at the Electrode-Semiconductor Interface Enhance the Activity of Bismuth Vanadate for Solar-Driven Glycerol Oxidation

Abstract

This study demonstrates that the integration of plasmonic palladium (Pd) nanoparticles between a BiVO₄ coating and an electrode interface can significantly improve solar-driven hydrogen production and glycerol oxidation. Pd nanoparticles of controllable shape, size and coverage were produced using a novel aerosol-assisted chemical vapour deposition (AACVD) synthetic route and then coated by BiVO₄ using the same technique. The nanoparticles enhance visible light absorption and crystallinity, increasing the photocurrent density at 1.23 V_RHE from 0.62 mA cm⁻² in bare BiVO₄ without glycerol to up to 1.58 mA cm⁻² in BiVO₄-coated Pd for experiments in 0.5 M glycerol. The incident photon-to-current conversion efficiency (IPCE) was also substantially boosted from ~ 15% to ~ 40% at 400 nm. Ultra-fast transient absorption spectroscopy suggests that Pd introduces additional charge transfer pathways, including hot electron injection and plasmon-coupled states, which prolong carrier lifetimes and suppress recombination. These combined effects provide a promising strategy to improve the efficiency and durability of photoelectrochemical devices for sustainable fuel generation and selective organic oxidation reactions.