▎ 摘　　要

NOVELTY - A particulate-form composite of iron compound and graphene oxide comprises iron compound. The content of iron in the composite is 0.1-50 %mass. The particle diameter of iron compound is 0.1-10 nm. The particle diameter of primary particle of particulate-form composite is 0.1-100 microns. Absorption derived from hydroxyl group, carbonyl group and iron-oxygen group at 701 cm-1 vicinity does not exist in infrared absorption spectrum of composite. Absorption derived from group having carbon-oxygen bond exists in infrared absorption spectrum. The iron compound is supported on graphene oxide. USE - Particulate-form composite of iron compound and graphene oxide is used as photocatalyst in apparatus for producing hydrogen (all claimed), and active ingredient of electrode for electrolysis of water. ADVANTAGE - The particulate-form composite of iron compound and graphene oxide is economical, and has excellent catalytic activity and hydrogen-producing efficiency, and can be recovered easily, and efficiently enables manufactured of hydrogen by economical and environmentally-friendly process. The electrode obtained using the particulate-form composite of iron compound and graphene oxide is economical. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) manufacture of particulate-form composite of iron compound and graphene oxide, which involves suspending iron compound and graphene oxide in an inert solvent, and irradiating an ultraviolet light and a visible ray to the resultant suspension; (2) photocatalyst, which comprises composite and graphene oxide; and (3) manufacture of hydrogen, which involves mixing photosensitizer and/or electron donor and water and/or alcohol and irradiating light in presence of composite.