Enhanced hydrogen generation from methanol aqueous solutions over Pt/MoO3/TiO2 under ultraviolet light

Abstract

The photocatalytic activity in hydrogen production from methanol reforming can be significantly enhanced by Pt/MoO3/TiO2 photocatalysts. Compared with Pt/P25, the photocatalytic activity of optimized Pt/MoO3/TiO2 shows an evolution rate of 169 mu mol/h/g of hydrogen, which is almost two times higher than that of Pt/P25. XRD and Raman spectra show that MoO3 are formed on the surface of TiO2. It is found that with the bulk MoO3 just formed, the catalyst shows the highest activity due to a large amount of heterojunctions and the high crystallinity of MoO3. The HRTEM image showed a close contact between MoO3 and TiO2. It is proposed that the Z-scheme type of heterojunction between MoO3 and TiO2 is responsible for the improved photocatalytic activity. The heterojunction structure of MoO3/TiO2 does not only promote the charge separation, but also separates the reaction sites, where the oxidation (mainly on MoO3) and reduction (on TiO2) reactions occurred. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.