WPI, International Institute for Carbon-Neutral Energy Research (WPI-I2CNER),
Kyushu University, Fukuoka 819-0395, Japan
Photocatalysts such as TiO2, ZnO and perovskites are currently receiving significant attention for acceleration of chemical reactions under light (such as hydrogen production from water or decomposition of organic compounds). Despite good photocatalytic features of these oxides, their application is limited to the ultraviolet (UV) range of sunlight due to their large optical bandgap. This talk briefly explains how application of severe plastic deformation (SPD) to these oxides can reduce their bandgap and activate them under visible light. The bandgap narrowing of these photocatalysts by SPD processing is mainly due formation of lattice defects and high-pressure phases.