Dye-sensitized solar cells (DSSCs) have received the tremendous interests as one of the promising candidates for low-cost and clean energy conversion devices. A standard DSSCs mainly consists of dye-sensitized TiO2 photoanode, counter electrode (CE), and electrolyte containing redox couple such as iodide/tri-iodide couple. Platinum (Pt) as CE catalyst is widely used to catalyze the reduction of iodide/tri-iodide couple, which results in a relatively high cost of DSSCs simply because Pt is one of the most expensive materials available now. As such, the alternatives to Pt with high conductivity and activity are highly desired. In this regard, chemical converted graphene that can be abundantly produced at low cost, shows high electrical conductivity inherited from the pristine graphene and good reduction activity for redox species derived from defects, which makes it a promising candidate of CE for DSSCs. Nevertheless, how to optimize the graphene structure and tune its conductivity and catalytic activity with an aim of further improving the conversion efficiency still remains a challenge. we report a series of approaches to the synthesis of G-based materials with high electrochemical performances including B-doped G, ionic liquid-grafted graphene oxide to B,N co-doped G, and G film-mediated MoS2/G nanohybrids, showing a high conversion efficiency that is superior or comparable to that of Pt CE.

Dye-sensitized solar cells (DSSCs) have received the tremendous interests as one of the promising candidates for low-cost and clean energy conversion devices. A standard DSSCs mainly consists of dye-sensitized TiO2 photoanode, counter electrode (CE), and electrolyte containing redox couple such as iodide/tri-iodide couple. Platinum (Pt) as CE catalyst is widely used to catalyze the reduction of iodide/tri-iodide couple, which results in a relatively high cost of DSSCs simply because Pt is one of the most expensive materials available now. As such, the alternatives to Pt with high conductivity and activity are highly desired. In this regard, chemical converted graphene that can be abundantly produced at low cost, shows high electrical conductivity inherited from the pristine graphene and good reduction activity for redox species derived from defects, which makes it a promising candidate of CE for DSSCs. Nevertheless, how to optimize the graphene structure and tune its conductivity and catalytic activity with an aim of further improving the conversion efficiency still remains a challenge. we report a series of approaches to the synthesis of G-based materials with high electrochemical performances including B-doped G, ionic liquid-grafted graphene oxide to B,N co-doped G, and G film-mediated MoS2/G nanohybrids, showing a high conversion efficiency that is superior or comparable to that of Pt CE.