Synthesis of NiCo_2S_4 nano-spheres as efficient counter electrodes for the application of dye sensitized solar cells

摘要

The new 3-D spongy NiCo_2S_4 nanospheres have been successfully fabricated by a temperate hydro-thermal method assisted sulfuration procedure and were used as counter electrode (CE) for dye-sensitized solar cells (DSSCs). The electrochemical tests such as cyclic voltam-metry, electrochemical impedance spectra analysis, and Tafel curve measurements, indicated that the NiCo_2S_4 nanospheres electrode possesses high conductivity, low charge transfer resistance at the electrolyte-electrode interface, excellent electrocatalytic activity, and fast reaction kinetics for the I~-/I~(3-) redox reaction for DSSCs. Furthermore, the DSSC fabricated using the NiCo_2S_4 nanostructure CE exhibits an efficiency of 6.47% comparing the convention Pt with 6.33% as reference. The results indicated that the NiCo_2S_4 nanostructure CE can display an excellent efficiency comparable to the Pt CE. Consequently, it is promising to substitute Pt CE for the NiCo_2S_4 nanostructure in the future.