Photocatalytic H2 production from aqueous methanol solutions using metal-co-catalysed Zn2SnO4 nanostructures

The activity of nanocrystalline Zn2SnO4 for photocatalytic hydrogen production from methanol aqueous solutions has been explored. A co-precipitation method starting from metal salts and a mild base as precipitating agent was used to obtain highly crystalline nanosized Zn2SnO4 with cubic inverse spine! structure. In-situ photodeposition of Pt and Au nanoparticles as co-catalysts was performed prior to the photocatalytic reaction. The obtained materials have been characterised by XRD, TEM, N-2 adsorption isotherms and ICP-OES, Raman, UV-vis and photoluminescence spectroscopies. Bare Zn2SnO4 gives rise to hydrogen release from a methanol aqueous solution without catalyst deactivation. This photocatalytic activity is remarkably increased with the deposition of platinum. In contrast, the use of gold as co-catalyst increases the activity only slightly, with a lower hydrogen production than a Pt-loaded sample with the same nominal metal content. An improved charge separation and the activity of Pt as hydrogen evolution catalyst are invoked to account for the present findings. (C) 2016 Elsevier B.V. All rights reserved.