Mesoporous NiCo2O4 networks with enhanced performance as counter electrodes for dye-sensitized solar cells.

The performance of a dye-sensitized solar cell (DSSC) is strongly influenced by the catalytic performance of its counter electrode (CE) materials. Platinum (Pt) is conventionally used as the CE for DSSCs, but it is precious and is readily corroded by the iodide/triiodide electrolyte. Herein, mesoporous NiCo2O4 networks with different types of building blocks were prepared by electrospinning of a composite solution followed by annealing in air, and their performances as CEs in DSSCs were investigated. The honeycomb-like NiCo2O4 exhibited better performance than the nanotube ones, showing a photoelectric conversion efficiency of 7.09% which is higher than that of a standard Pt CE (7.05%) under the same conditions. The enhanced electrode performance was attributed to the relatively larger surface area and higher conductivity. The preparation methods demonstrated in this study are scalable and would pave the way for practical applications of Pt-free DSSCs.