▎ 摘　　要

Hierarchical Cu2S microspheres wrapped by reduced graphene oxide (RGO) nanosheets are prepared via a one-step solvothermal process. The amount of graphene oxide used in the synthesis process has a remarkable effect on the features of Cu2S microspheres. Compared to Pt and Cu2S electrodes, RGO-Cu2S electrodes show better electrocatalytic activity, greater stability, lower charge-transfer resistance, and higher exchange current density. As expected, RGO-Cu2S electrodes exhibit superior performance when functioning as counter electrodes in CdS/CdSe quantum-dot sensitized solar cells (QDSSCs) using a polysulfide electrolyte. A power conversion efficiency up to 3.85% is achieved for the QDSSC employing an optimized RGO-Cu2S counter electrode, which is higher than those of the QDSSCs featuring Pt (2.14%) and Cu2S (3.39%) counter electrodes.