▎ 摘　　要

In present study, CoSe2, and CoSe2@N-doped graphene nanocomposite has been prepared in an inert atmosphere and used as a DSSC counter electrode. The fabricated nanocomposite was characterized using analytical techniques including FTIR, TGA, XRD, Raman, XPS, and BET. The assembled DSSC obtains a photoelectric conversion efficiency (PCE) of 7.65%, which is higher than the PCE (7.19%) of the Pt electrode assembly cell under the same conditions. The promising performance of the fabricated counter electrodes may be due to the excellent surface area of the nanocomposites, the doping of heteroatoms which provide the active sites to boost the catalytic activities towards I-3(-) reduction. These results illustrate the rational design of CoSe2@N-doped graphene nanocomposite and has great potential for replacing noble Pt for the reduction of I-3(-) in DSSCs.