Metal doped TiO2 decorated carbon nanostructured materials as an emerging photocatalysts for solar fuels production

The concept of photocatalytic CO2 and H2O conversion to solar fuels and value-added products provides simultaneous solution for increased energy demands and environmental problems. However, the lack of efficient photocatalysts restrains the large-scale development of photocatalytic technology. In the present study, noble (Pt and Au) and transition metal (Ni) doped nanoflakes assembled on TiO2@carbon microrods with high surface area and rutile crystal structure is prepared via fast, versatile solvothermal method. The photocatalytic performance of the prepared nanocomposites was evaluated in two photocatalytic systems: CO2 reduction and hydrogen production via photoreforming. Pt-doped catalyst showed enhanced hydrogen production efficiency and increased CH4 selectivity, while Ni-doped catalyst exhibited remarkable CO2 reduction activity with higher selectivity towards CO. The mechanism of Pt-promoted CH4 formation and Ni- and Au-promoted CO formation was thoroughly discussed regarding kinetic and thermodynamic parameters.