Effect of Synthesis Conditions of Platinum/Reduced Graphene Oxide Nanocomposites on the Electrochemical Behaviors of Cathodes in Dye-Sensitized Solar Cells

This study deals with the preparation and characterization of platinum/reduced graphene oxide (Pt/rGO) as an efficient cathode for dye-sensitized solar cells. Herein, the Pt/rGO material was synthesized by co-precipitation from hexachloroplatinic acid (H2PtCl6) and graphene oxide (GO) precursors. The fabrication of cathodes from Pt/rGO composite paste was carried out using screen-printing paste. The electrochemical behaviors of as-prepared cathodes were analyzed by cyclic voltammetry; the performance of fabricated DSSCs was measured by current density–voltage (J-V) curves and electrochemical impedance spectroscopy. The structural characteristics of the Pt/rGO binary composites were confirmed by Fourier-transform infrared spectroscopy, Raman spectroscopy, x-ray diffraction (XRD), and transmission electron microscopy. Empirical data showed that choosing ascorbic acid as a reducing agent at a ratio of 5:1 between ascorbic acid weight and precursor mixture weight, as well as a GO weight percentage of 20% fabricated DSSCs successfully with a conversion efficiency of 6.25%, which was approximately 90% compared to that of pure commercial Pt material. Characterization results indicated that the Pt nanoparticles were homogeneously distributed on the rGO sheets with an average diameter of less than 25 nm. The Pt/rGO hybrid composite is highly expected to replace Pt in the fabrication of cathodes in DSSCs for low-cost DSSC production in the promising future.