One-Step Hydrothermal Synthesis of Precious Metal-Doped Titanium Dioxide-Graphene Oxide Composites for Photocatalytic Conversion of CO 2 to Ethanol.

We utilized a one-step hydrothermal process for the synthesis of precious metal-doped titanium dioxide (TiO 2 )/graphene oxide (GO) composites. The metal-doped TiO 2 /GO composites, including silver-TiO 2 /GO (Ag-TiO 2 /GO), palladium-TiO 2 /GO (Pd-TiO 2 /GO), and copper-TiO 2 /GO (Cu-TiO 2 /GO), were synthesized by mixing a metal precursor, titanium butoxide, and graphene oxide in a water-ethanol mixture in an autoclave hydrothermal reactor. The photocatalytic performance of the composites was tested in the photoreduction of carbon dioxide (CO 2 ) to ethanol. Ag-TiO 2 /GO, Pd-TiO 2 /GO, and Cu-TiO 2 /GO exhibited an ethanol production rate of 109, 125, and 233 μmol/g cat h, respectively. The outstanding performances of Cu-TiO 2 /GO can be attributed to a combined effect of key parameters, including optical band gap, crystallite size, and BET surface area.