Preparation of Electrochemically Reduced Graphene Oxide/ Bimetallic Cu-Pt Nanohybrid as Counter Electrode for Fabrication of Dye-Sensitized Solar Cell

This research was conducted to prepare Cu-Pt nanoparticles incorporated onto electrochemically reduce graphene oxide (ERGO) as the counter electrode (CE) material for the production of dye sensitized solar cell (DSSC). At first, GO was introduced by electrophoretic deposition method on the surface of fluorine doped tin oxide (FTO) electrode. Then, GO nanosheets were converted to ERGO nanosheets by chronoamperometery technique. The Cu nanoparticles were grown on FTO/GO electrode surface by a chronoamperometric method from CuSO4 (1mM) aqueous solution at specified reduction potential of -0.18 V and during an optimized time of 50 s. Then, the electrode was immersed in H2PtCl6 (2mM) to deposit Pt nanoparticles through galvanic replacement with Cu particles. The provided electrodes were studied by FESEM, FT-IR, EDX and ICP spectroscopy. FESEM analysis shows that the surface of the ERGO electrode are decorated with bimetallic Cu-Pt nanoparticles. Some features of CE such high catalytic activity for the reduction of triiodide to iodide (I- / I3-) and a low charge transfer was investigated using electrochemical impedance (EIS), cyclic voltammetry (CV) and Tafel polarization. Also, the TiO2 photoanode was prepared onto pre-cleaned FTO glass by using a doctor-blade technique. The photoanode and ERGO/Cu-Pt CE were assembled into cell with a Surlyn. Finally, the energy conversion efficiency of prepared cell was investigated using an AM 1/5 beam.