2013 年 34 巻 7 号 p. 368-373
There is often the lack of reproducibility in photocatalysis, the reason for which is partly the fact that the photocatalysis is not simple photo-induced catalysis on the surface, but rather the result of the total performance of the device-like system that involves bulk diffusion of the photo-excited minority carrier and its charge transfer across the interface. Therefore very small amount of unexpected defects and impurities in a photocatalyst, which could hardly be detected by the conventional surface science analysis techniques, would essentially make it difficult to reproduce its semiconductor properties and hence the resultant photocatalysis. In this review, a new approach based on a recent progress in oxide epitaxy to precision structural control of photocatalysts is proposed and the possible effects of surface structures, defects and impurities on the photocatalysis will be discussed from the viewpoints of semiconductor physics as well as surface science, showing some of our experimental demonstrations.