Photocatalytic Hydrogenation on Semiconductor Particles

Abstract

Photocatalytic hydrogenation on semiconductor particles is a quite unique methodology compared to the conventional hydrogenations such as catalytic hydrogenation on metals or homogeneous catalysis using metal complexes. The catalysis can be defined as a light- driven redox reaction at a solid/liquid or a solid/gas interface. The semiconductor photocatalysis have been mainly developed by researchers in the areas of photochemistry, electrochemistry, and heterogeneous catalysis. Since Fujishima and Honda have discovered the photoelectrochemical water splitting upon titanium dioxide (TiO2 ) photoelectrode in the early 1970’s [1], the heterogeneous photocatalysis, especially using TiO2 , has been applied to various fields such as storage of solar energy [2,3], environmental purification [3,4], and specific surface properties of self-cleaning, self- sterilizing, and anti-fogging induced by incident light [5]. The photocatalysis has also attracted much attention with respect to inducing characteristic organic transformations since 1970’s [6-11]. Among those, the photocatalytic hydrogenation of ethene and ethyne on TiO2 was already reported in 1975 [12]. Since then, the reductive photocatalysis has been applied to the hydrogenation for several organic compounds having various double or triple bonds.