Computational study of H2O adsorption and hydrolysis on (ZnO)3 nanoclusters deposited on graphene and graphene oxides

Graphene and graphene oxide (GO) based metal oxides could play an important role in photocatalysis using metal oxide catalysts. ZnO is a metal oxide with a 3.37 eV band gap and is a commercially cheaper photocatalyst than titanium oxide in the production of hydrogen (H2)by splitting water. The π conjugation structure of GO shows greater electron mobility and could enhance the photocatalytic performance of the ZnO catalyst by increasing the electron-hole separation. In this work, we use density functional theory at the B3LYP/DGDZVP2 level to study the impact of adsorbing (ZnO)3 on graphene and GO on the hydration and hydrolysis of water that precedes water splitting to produce H2 and O2 in the gas phase. We used 5 different GO models anchoring carboxyl, hydroxyl, and epoxy functional groups on separate layers of graphene. This study also compares the reaction pathway of H2 and O2 production from the hydrolyzed (ZnO)3 and GO1-(ZnO)3 in the gas phase using the same level of theory. 1