The effect of a counter electrode (CE), fabricated by hybridizing the platinum nanoparticle (PtNP) and the nanographite (NG) on a dye-sensitized solar cell (DSSC), has been studied in this work. The catalytic PtNP/NG composite film for a CE is prepared using aniline (ANI) monomers as a dispersing medium, followed by spin-coating and annealing processes. The PtNP/NG composite film owns a high catalytic ability of converting tri-iodide to iodide due to the large surface roughness of the film. Thus, the DSSC assembled with the corresponding CE gives enhanced short-circuit current density (J(SC)) and power-conversion efficiency (eta) of 17.57 mA cm(-2) and 7.07%, respectively, while the corresponding values are 14.57 mA cm(-2) and 6.65% for a DSSC with a bare PtNP CE. Lower loading amounts of PtNPs for the PtNP/NG CE than those for the bare PtNP CE is demonstrated. Transmission electron microscopy (TEM) and UV/Vis absorption measurements are used to observe the dispersion of NGs in the solutions. X-ray diffraction (XRD) and Raman analyses are used to confirm the PtNP/NG composite film. The results are also substantiated by the characterizations of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM), and atomic force microscopy (AFM). (C) 2011 Elsevier Ltd. All rights reserved.