▎ 摘　　要

A sandwich structural CoS/graphene sheet (CoS/GS) electrode was prepared by repeating electrophoretic deposition of graphene sheets and deposition of CoS nanoparticles. We found the graphene sheets play a key role in controlling the morphology of the nanostructure. The obtained CoS/graphene nanocomposite counter electrode has a high specific surface area and displays an excellent electrochemical activity toward the polysulfide electrolyte. Consequently, the quantum dot-sensitized solar cell based on CoS/GS counter electrode shows an improved photovoltaic performance. (C) 2013 Elsevier B.V. All rights reserved.