▎ 摘　　要

NOVELTY - A graphene-based molybdenum nitride-molybdenum carbide/cadmium sulfide composite photocatalyst comprises cadmium sulfide, and graphene, and molybdenum nitride or molybdenum carbide, or graphene-based molybdenum nitride-molybdenum carbide composite cocatalyst containing graphene, and molybdenum nitride or molybdenum carbide in weight ratio of 1:10-10:1, preferably 1:5-3:1, more preferably 1:2. The weight ratio of graphene-based molybdenum nitride-molybdenum carbide composite cocatalyst and cadmium sulfide is 1:50-1:5, preferably 1:20. USE - Graphene-based molybdenum nitride-molybdenum carbide/cadmium sulfide composite photocatalyst is used in photocatalytic/photoelectrocatalytic decomposition of water e.g. distilled water, deionized water, sea water, lake water and other aqueous solution for producing oxygen and hydrogen, and optoelectronic catalytic reaction (all claimed). ADVANTAGE - The graphene-based molybdenum nitride-molybdenum carbide/cadmium sulfide composite photocatalyst improves production of hydrogen by 20 times. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of graphene-based molybdenum nitride-molybdenum carbide/cadmium sulfide composite photocatalyst, which involves preparing graphene-based molybdenum nitride-molybdenum carbide composite cocatalyst using urea as carbon and nitrogen sources by urea-glass method, and loading the cocatalyst on cadmium sulfide by hydrothermally processing, precipitating, mechanical mixing, loading, chemical crosslinking, or chemical deposition method; and (2) application of graphene-based molybdenum nitride-molybdenum carbide/cadmium sulfide composite photocatalyst for photocatalytic or photoelectrocatalytic decomposition of water.