A general approach towards carbon supported metal carbide composites for cobalt redox couple based dye-sensitized solar cells as counter electrodes

In this work, a feasible method is put forward to synthesize carbon supported transition metal carbide composites (Cr3C2-C, Mo2C-C, WC-C, VC-C, NbC-C, TaC-C, and TiC-C, et al.) by utilizing metal chlorides as metal sources, and phenolic resin as carbon source. As demonstrated by the cyclic voltammetry results, the carbon supported carbide composites present higher peak current densities as well as lower peak-to-peak separations. Moreover, the electrochemical impedance spectroscopy results indicate lower charge transfer resistance over the pristine carbides. Compared with the carbides, the carbon supported carbide composites show much higher catalytic activities towards the cobalt redox couple regeneration in dye-sensitized solar cells (DSCs) as counter electrode. In the DSCs system, the devices using the TiC-C, VC-C, and WC-C composite counter electrodes display power conversion efficiencies of 8.85%. 9.75% and 9.42%, respectively, which are much higher than those of the counterparts utilizing TiC, VC and WC counter electrodes.