Synthesis of graphene-CoS electro-catalytic electrodes for dye sensitized solar cells

A large CoS-implanted graphene (G-CoS) film electrode was prepared using chemical vapor deposition followed by successive ionic layer absorption and reaction. HRTEM and AFM show that CoS nanoparticles are uniformly implanted on the graphene film. Furthermore, the G-CoS electro-catalytic electrode is characterized in a dye sensitized solar cells (DSSC) and is found to be highly electro-catalytic towards iodine reduction with low charge transfer resistance (Rct ∼5.05 Ω cm2) and high exchange current density (J0∼2.50 mA cm−2). The improved performance compared to the pristine graphene is attributed to the increased number of active catalytic sites of G-CoS and highly conducting path of graphene. The comprehensive G-CoS synthesis process is a simple and scalable process which can easily adapt for large scale electro-catalytic film fabrication for several other electro-chemical energy harvesting and storage applications.