PHOTOCATALYST SEMICONDUCTOR ELEMENT, PHOTOCATALYTIC OXIDATION-REDUCTION REACTOR, AND METHOD FOR PERFORMING PHOTOELECTROCHEMICAL REACTION

摘要

PROBLEM TO BE SOLVED: To provide a photocatalyst semiconductor element which has durability against etching and, further, enables an oxidation-reduction reaction to occur by light irradiation with higher energy conversion efficiency, and to provide a photocatalytic oxidation-reduction reactor and a method for performing a photoelectrochemical reaction using the reactor.SOLUTION: There is provided a photocatalyst semiconductor element for a photocatalytic oxidation-reduction reaction, comprising: a light absorption layer comprising GaN and/or InGaN laminated on a substrate via a carrier mobile layer comprising n-type GaN; and a cocatalyst comprising CuO supported on a surface of the light absorption layer. In the photocatalyst semiconductor element, when the light absorption layer comprises InGaN, a rate of coverage of the light absorption layer surface by the cocatalyst comprising CuO is preferably 0.7 to 4 area%. When the light absorption layer comprises GaN, the rate of coverage of the light absorption layer surface by the cocatalyst comprising CuO is preferably 0.4 to 2 area%.