▎ 摘　　要

Platinum-free and novel hybrid counter electrode is an important part of dye-sensitized solar cells (DSSCs). More and more researches reported that transitional metal oxide nanoparticles can be used as CEs in DSSCs. However, they are ready to be corroded by electrolyte, leading to worse stability in catalytic activities for triiodide reduction in the cyclic voltammetry (CV) test. Multiwall carbon nanotubes (MWCNTs) have tangled network, exceptional specific surface area, and unique hollow composition can be higher for use as a CE material. The electrochemical performance analysis indicates that the Co3O4 nano flakes and functionalized multiwall carbon nanotubes (f-MWCNTs), wrapped with N-doped reduced graphene oxide (Co3O4@f-MWCNTs@N-RGO) electrode has lower charge transfer resistance (R-ct) on the electrolyte/electrode interface and higher catalytic ability than bare Co3O4 nano flakes. Power conversion efficiency (PCE) of the prepared hybrid has been achieved up to 8.42%, in contrast to the platinum-based counter electrode (PCE = 7.81%) used in DSSCs. Besides, Co3O4@f-MWCNTs with N-RGO hybrid material shows strong catalytic activities for triiodide reduction, superior to Co3O4 nano flakes in the CV test.