The invention relates to a preparation method of a 
solar light splitting water 
hydrogen production catalyst without 
noble metal as a cocatalyst.  Specifically, 
graphene is used as a cocatalyst to prepare 
semiconductor nanoparticle-
graphene composite photocatalysts, including CdS-
graphene composites and TiO2-graphene composites.  The 
hydrogen production efficiency of the photocatalyst with graphene as the cocatalyst is comparable to or even higher than that of the photocatalyst containing the same 
mass of 
noble metal Pt under the same 
hydrogen production conditions.  
Graphene materials have good 
electron aggregation and transport functions, which promote the effective separation of electrons and holes, reduce the probability of 
proton recombination, and increase the photocatalytic efficiency of photocatalysts and the efficiency of photo-splitting water to produce hydrogen; and the preparation method of graphene materials is simple  , cheaper than precious metals, and has no 
pollution to the environment, which is conducive to large-scale preparation and production.  The preparation of photocatalysts using graphene as a cocatalyst has opened up a new method for reducing the cost of 
hydrogen production from 
solar energy and improving the efficiency of 
hydrogen production by photolysis of water.