Light-assisted synthesis of Au/TiO2 nanoparticles for H2 production by photocatalytic water splitting

A series of Au/TiO2 photocatalysts was synthesized via the light assistance through the photo-deposition for H2 production by photocatalytic water splitting using ethanol as the hole scavenger. Effect of solution pH in the range of 3.2-10.0 on the morphology and photocatalytic activity for H2 production of the obtained Au/TiO2 photocatalysts was explored. It was found that all Au/TiO2 photocatalysts prepared in different solution pH exhibited comparable anatase fraction (~0.84-0.85) and crystallite size of TiO2 (21-22 nm), but showed different quantity of deposited Au nanoparticles (NPs) and other properties, particularly the particle size of the Au NPs. Among all prepared Au/TiO2 photocatalysts, the Au/TiO2 (10.0) photocatalyst exhibited the highest photocatalytic activity for H2 production, owning to its high metallic state and small size of Au NPs. Via this photocatalyst, the maximum H2 production of 296 mmol (~360 mmol/g,h) was gained at 240 min using the 30 vol% ethanol as the hole scavenger at the photocatalyst loading of 1.33 g/L under the UV light intensity of 0.24 mW/cm2 with the quantum efficiency of 61.2% at 254 nm. The loss of the photocatalytic activity of around 20% was observed after the 5th use.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

A series of Au/TiO2 photocatalysts were synthesized using ethanol as the hole scavenger for H2 production by photocatalytic water splitting. The effect of solution pH on the morphology and photocatalytic activity of the photocatalysts was investigated. It was found that the Au/TiO2 photocatalysts prepared under different solution pH exhibited similar anatase fraction and TiO2 crystallite size, but varied in the quantity and size of deposited Au nanoparticles. Among all the prepared photocatalysts, Au/TiO2 (10.0) showed the highest photocatalytic activity due to its high metallic state and small size of Au nanoparticles.