METHOD FOR MANUFACTURING MULTILAYER THIN FILM TYPR PHOTOCATALYST AND METHOD FOR PRODUCING HYDROGEN USING THE PHOTOCATALYST

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a multilayer photocatalyst comprising a compound semiconductor thin film and having activity in the nearly entire wavelength area of sunlight, and to provide a method for producing hydrogen using the multilayer photocatalyst. SOLUTION: An electrically conductive substrate as a cathode, together with a reference electrode and a counter electrode, is immersed in a solution containing chemical species as starting materials of compound semiconductors and a first compound semiconductor layer and a second compound semiconductor having a band gap different from that of the first compound semiconductor layer are electrodeposited and fixed on the surface of the substrate in order or while gradually varying the mixing ratio between both the semiconductors to manufacture the objective multilayer thin film type photocatalyst. Gaseous hydrogen is produced by immersing the photocatalyst in an alkaline solution and irradiating the solution with light.