A Facile Synthesis of Ternary Nickel Iron Sulfide Nanospheres as Counter Electrode in Dye-Sensitized Solar Cells.

The incorporation of a foreign metal into a material may adjust the surface electronic structure and promote charge transfer, which then ultimately improves electrical conductivity and electrocatalytic performance because of the possible charge delocalization between the metal cations. As a result, for the first time, ternary nickel iron sulfide nanospheres have been successfully fabricated through a two-step solvothermal approach with the help of glucose (Ni0.5 Fe0.5 S2 /C). Subsequently, the electrochemical performance and electrocatalytic activity of Ni0.5 Fe0.5 S2 /C were evaluated by electrochemical impedance spectroscopy, Tafel polarization and cyclic voltammetry, indicating high electrical conductivity and great electrocatalytic activity. Ni0.5 Fe0.5 S2 /C was employed as a counter electrode for dye-sensitized solar cells, and exhibited higher power conversion efficiency (6.79 %) than the device with Pt CE (6.31 %) under full sunlight illumination (100 mW cm-2 , AM 1.5G).