▎ 摘 要
Graphene with a cellular framework structure (GFs) exhibits unique advantages that facilitate quasiisotropic electron conduction, promote ion diffusion, and induce transport. GFs can act as an ideal support to uniformly disperse platinum (Pt) nanoparticles to better catalyze molecular or ionic reactions, which are intrinsically important for an effective counter electrode (CE) in dye-sensitized solar cells (DSSCs) systems. The power conversion efficiency of optimized DSSCs with GFs CE is 6.15%, which is comparable to that of the conventional Pt CEs (6.71%) and markedly than that of 2D graphene sheets CE (3.60%). More importantly, the GFs-Pt composite CEs could achieve an efficiency of 7.26%. The dynamic discipline behind the improved performance of GFs-based CEs in DSSCs is systematic investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Tafel polarization analysis, revealing that the better diffusion coefficient of the I(3)(-)ion and lower charge transfer resistance at CE interface result in the higher efficiency of GFs based solar cells. (C) 2015 Elsevier Ltd. All rights reserved.