A novel photo-thermochemical cycle of water-splitting for hydrogen production based on TiO2-x/TiO2

The traditional two-step thermochemical cycle of water-splitting that is based on metal oxide redox pairs requires a high reaction temperature. In this study, we introduced a photochemical reaction into this thermochemical cycle and established a novel photo-thermochemical cycle. In this new cycle, the process by which metal oxides are reduced through concentrated solar energy is replaced with a photochemical reaction while water is still dissociated via a thermochemical reaction. Thus, photo-thermochemical cycles that combine these two reactions can be initiated at relatively low temperatures, unlike thermochemical cycles operated at extremely high temperatures. In this research, TiO2 was used as the catalyst, experiments were conducted to evaluate the feasibility of the proposed cycle, and a preliminary mechanism was developed for this cycle. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.