Photocatalytic hydrogen evolution from water over hafnium oxyphosphate

Hafnium oxyphosphate was prepared as a novel photocatalyst for hydrogen production from water. Here, Hf4+ with d(0) electronic configuration was selected as the constituent cation, because efficient photocatalysts generally contain d(0) or d(10) metal cations. In addition, most phosphates are reported to have high photoreduction ability of crater due to their wide bandgap compared to oxides. By using Hf2O(PO4)(2), hydrogen gas was generated from water under the ultraviolet light irradiation, while a simple hafnium oxide, HfO2, did not show a hydrogen evolution ability. The hydrogen production rate of Hf2O(PO4)(2) was estimated to be 800 mu mol.h(-1). Also, oxygen gas evolution was observed for Hf2O(PO4)(2). (C) 2019 The Ceramic Society of Japan. All rights reserved.