rGO Sheets/ZnFe 2 O 4 Nanocomposities as an Efficient Electro Catalyst Material for I 3 − /I − Reaction for High Performance DSSCs

In this paper, Reduced Graphene Oxide (rGO)/ZnFe 2 O 4 (rZnF) nanocomposite is synthesized by a simple hydrothermal method and employed as a counter electrode (CE) material for tri-iodide redox reactions in Dye sensitized solar cells (DSSC) to replace the traditional high cost platinum (Pt) CE. X-ray diffraction analysis and High resolution Transmission electron microscopy, clearly indicated the formation of rZnF nanocomposite and also amorphous rGO sheets were smoothly distributed on the surface of ZnFe 2 O 4 (ZnF) nanostructure. The rZnF-50 CE shows excellent electro catalytic activity toward I 3 − reduction, which has simultaneously been confirmed by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization measurements. A DSSC developed by rZnF-50 CE (η = 8.71%) obtained quite higher than the Pt (η = 8.53%) based CE under the same condition. The superior performances of rZnF-50 CE due to addition of graphene in to Spinel (ZnF) nanostructure results in creation of highly active electrochemical sites, fast electron transport linkage between CE and electrolyte. Thus it’s a promising low cost CE material for DSSCs.