Photocatalytic H2 production by ethanol photodehydrogenation: Effect of anatase/brookite nanocomposites composition

In view of the sustainable H-2 production, development of more efficient catalysts for photocatalytic reforming of oxygenated compounds is required. In this study, we report the preparation of TiO2 nanocomposite with anatase/brookite composition prepared by hydrothermal treatments of Na-titanate precursor. The anatase/brookite ratio can be modulated changing the synthetic parameters, i.e. precursor/water mass-to volume ratio and hydrothermal treatment duration. The obtained materials present well crystallized particles with polyhedral morphology. The anatase/brookite ratio in the nanocomposite affects the mean size of Pt nanoparticles grown by photodeposition and the photocatalytic activity in H-2 production by photodehydrogenation of ethanol, with multiphasic materials presenting smaller Pt nanoparticles and higher H-2 production. The present anatase/brookite nanocomposites show higher H-2 production normalized to the surface area with respect a reference TiO2 prepared by conventional sol-gel synthesis, suggesting that the present materials might expose a higher fraction of highly reactive facets instead of the most thermodynamically stable. (C) 2015 Elsevier B.V. All rights reserved.