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 bismuth vanadate (BVO) coating and an electrode interface can significantly improve solar-driven 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 with BVO using the same technique. The nanoparticles enhanced visible light absorption and crystallinity. At 1.23 V_RHE, the photocurrent density of bare BVO increased from 0.62 mA cm⁻² in the absence of glycerol to 1.20 mA cm⁻² with 0.5 M glycerol. When Pd nanoparticles were incorporated beneath BVO, the photocurrent further increased from 0.86 mA cm⁻² without glycerol to 1.58 mA cm⁻² with 0.5 M glycerol, and the incident photon-to-current conversion efficiency (IPCE) boosted from ∼15% to ∼40% at 400 nm. Ultra-fast transient absorption spectroscopy suggests that the addition of Pd nanoparticles 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.