Au-nps embedded z-scheme wo3/tio2 nanocomposite for plasmon-assisted photocatalytic glycerol-water reforming towards enhanced h-2 evolution

Abstract

Au-NPs-embedded Z-scheme WO3/TiO2 hetero-junction for boosting photocatalytic H-2 evolution from glycerol-water mixture under visible light has been investigated. The composite samples, synthesized by a sol-gel assisted photo-deposition method, gave higher visible light absorption through Surface Plasmon Resonance (SPR), larger BET surface area and hindered recombination of charge carrier. Highest H-2 evolution rate of 17200 ppm h(-1) gcat(-1) was obtained over 0.5%Au-loaded WO3/TiO2 which was 4.46 and 5.89 folds higher than WO3/TiO2 and TiO2, respectively. This divulges that constructing WO3/TiO2 Z-scheme hetero-junction adjusted redox potential, while decorating plasmonic Au-NPs enables faster charges separation with higher visible-light absorption through SPR, resulting in superior H-2 production. In addition, both water splitting and photocatalytic glycerol reforming contributed towards excellent H-2 formation. The apparent quantum yield of 28.3% (lambda - 420 nm) was attained and catalyst prevailed photo-stability for H-2 evolution in cyclic runs. This study provides new insight about constructing plasmonic assisted Z-scheme assembly for solar fuels production.