Room-temperature photocatalytic methanol fuel cell based on one-dimension semiconductor photoanode: intrinsic mechanism of photogenerated charge separation

We report a photocatalytic methanol fuel cell (PMFC) based on one-dimension TiO₂, ZnO and α-Fe₂O₃ photoanode for efficient methanol oxidation reaction at room temperature. Electro-chemical analysis along with Mott-Schottky (MS) equation and cyclic voltammetry (CV) revealed thermodynamic feasibility of charge transfer and methanol oxidation in the system. Time-resolved surface photovoltage (SPV) transient gave a dynamic information of photogenerated charge carriers, which is related to types of materials, sample thickness and light intensity. The ZnO-based PMFC got the maximum short-circuit current of 1.82 mA cm^-2 and TiO₂-based fuel cell had an open-circuit voltage of 1.34 V. This study opens an available field to develop power cells taking advantage of both chemical energy and solar energy.