Facile formation of SnO2–TiO2 based photoanode and Fe3O4@rGO based counter electrode for efficient dye-sensitized solar cells

Abstract

This research work analyzes the effect of modification on photovoltaic parameters of a dye-sensitized solar cell (DSSC) by customizing its photoanode by SnO2–TiO2 nanocomposite and counter electrode (CE) by a low-cost platinum (Pt) free hybrid Fe3O4@rGO nanocomposite. A facile solvothermal synthesis technique was adopted for the preparation of SnO2–TiO2 and hybrid Fe3O4@rGO nanocomposites. The in-depth characterization of the newly synthesized nanocomposites was executed by SEM, EDS, XRD, TGA, BET and UV–Vis techniques to verify the formation of nanocomposites. The photovoltaic parameters were examined by plotting J-V (current-voltage) curves, EIS Nyquist curves and IPCE spectra. The SnO2–TiO2 nanocomposite based photoanode exhibited favorable power conversion efficiency (PCE) of 3.28% with conventional Pt and 1.96% with hybrid Fe3O4@rGO CE respectively in DSSC. The DSSC approached to 60% PCE of the platinum with hybrid Fe3O4@rGO CE. The reasonable efficiency is attributed to improved charge transfer and enhanced dye-loading due to formation of wide band gap SnO2–TiO2 nanocomposite and by the uniform dispersion of Fe3O4 nanoparticles anchored at rGO nanosheets. The results suggested that the synergistic combination of SnO2–TiO2 photoanode and hybrid Fe3O4@rGO CE exhibited a very reasonable efficiency quite comparative to Pt in DSSC and thus can prove to be as an effective substituent of conventional scarce Pt.