The enthalpy change for water splitting reaction is 116.5 kcal/mol at 298.15 K in the gas phase showing that the reaction is strongly endothermic, and requires ≈ two photons of 500 nm wavelength to overcome the enthalpy difference 6 of reaction 1. However, on examining the mechanism of reaction 1 using TiO 2 and different metal oxide catalysts, water splitting is preceded by hydration of the catalyst and hydrolysis of water in exothermic reactions that further lower the enthalpies of reactants thereby increasing the enthalpy for water splitting even more than what is needed for the direct dissociation of two molecules of water to form two molecules of hydrogen and one of oxygen according to the equation 1 in which hydration and hydrolysis are intermediate steps. It is important to study the precursors to water splitting as already done by Fang et al for (TiO 2 ) n=1 to 4 and other metal oxides to get a clearer picture of the steps preceding water splitting in the gas phase, using metal oxide catalysts. We have previously studied the (ZnO) n=3 nanocatalyst as a substitute for TiO 2 as a catalyst and this paper provides examples of attempts to enhance the catalytic property of ZnO trimer by deposition on graphene and various synthetic graphene oxides. Graphene