Synthesis of NiCo2S4 nano-spheres as efficient counter electrodes for the application of dye sensitized solar cells

The new 3-D spongy NiCo2S4 nanospheres have been successfully fabricated by a temperate hydrothermal method assisted sulfuration procedure and were used as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The electrochemical tests such as cyclic voltammetry, electrochemical impedance spectra analysis, and Tafel curve measurements, indicated that the NiCo2S4 nano-spheres electrode possesses high conductivity, low charge transfer resistance at the electrolyte–electrode interface, excellent electrocatalytic activity, and fast reaction kinetics for the I−/I3− redox reaction for DSSCs. Furthermore, the DSSC fabricated using the NiCo2S4 nanostructure CE exhibits an efficiency of 6.47% comparing the convention Pt with 6.33% as reference. The results indicated that the NiCo2S4 nanostructure CE can display an excellent efficiency comparable to the Pt CE. Consequently, it is promising to substitute Pt CE for the NiCo2S4 nanostructure in the future.