Fabrication of a Cu_2O/(rGO-TiO_2) Composite Film for Efficient Photocatalytic Hydrogen Production

A novel and environmentally friendly photocatalyst film, Cu2O/(rGO-TiO2), was synthesized by introducing rGO into Cu2O and TiO2 composite. The composite catalyst film had a multi-layer structure and could effectively produce hydrogen and decompose organic matters simultaneously under solar light irradiation. Firstly, the Cu2O was prepared by electrochemical deposition. Then the GO was reduced to rGO in TiO2 suspension to fabricate the rGO-TiO2 particles. Finally, the rGO-TiO2 suspension was painted on the surface of Cu2O. The morphology of as-prepared composite film was analyzed with SEM and TEM; its crystal structure was examined with XRD and Raman and its optical characteristics was investigated with UV-Vis DRS and PL. The composite film was applied for hydrogen generation with 20% (volume percentage) methanol under 300 W Xe lamp irradiation. Compared with Cu2O-TiO2 film, the photocatalytic hydrogen production of the composite film (326 mmolh-1m-2) was improved (3.5 folds) significantly after coupling 1.0% (mass percentage) rGO to Cu2O-TiO2. Besides, the photocatalytic hydrogen productivity was also examined with different electron donors and with 20% methanol at different pH. The results showed that the highest hydrogen production rate was achieved in 20% (volume percentage) methanol with neutral pH.