Carbon Coated TiO_2 Photoanode for All-vanadium Redox Photoelectrochemical Cells as Efficient Solar Energy Storage Device

摘要

An all-vanadium redox photoelectrochemical cell with a carbon coated T1O_2 photoelectrode was designed to convert/store solar energy as a promising alternative to photogeneration of hydrogen. In this study, a facile high-temperature sintering approach was employed to tailor the amount of the carbon coating at the TiO_2 photoanode. Considerable enhancement in photocurrent has been observed using the carbon coated TiO_2 photoanode in the all vanadium photoelectrochemical system when compared to the carbon-free counterpart. Particularly, the photoanode containing 2.07 wt% of carbon displayed 40% improvement in photocurrent compared to the one with bare TiO_2 as the photoanode. It is proposed that the carbonaceous species created by high-temperature pyrolysis acted as a thin adsorption layer on the TiO_2 for vanadium redox to react with the photogenerated holes. Photocurrent enhancement of the carbon coated photoelectrodes is ascribed to a synergic effect between enhanced charge separation and high electronic conductivity.