Dynamics Investigation of Graphene Frameworks-Supported Pt Nanoparticles as Effective Counter Electrodes for Dye-Sensitized Solar Cells

•Firstly report the GFs-supported Pt nanoparticles as efficient CE for DSSCs.•An improved conversion efficiency of 7.26% is achieved, superior to that of Pt CE.•Reveal the dynamic discipline behind the improved efficiency of GFs based CE.

Graphene with a cellular framework structure (GFs) exhibits unique advantages that facilitate quasi-isotropic 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 I3− ion and lower charge transfer resistance at CE interface result in the higher efficiency of GFs based solar cells.

Graphical abstractGraphene frameworks provide excellent basic properties in promoting quasi-isotropic electron conduction and ion transport, providing additional catalytic reaction sites and also function as an excellent support, ultimately enhancing catalytic I3− ion reaction.Figure optionsDownload full-size imageDownload as PowerPoint slide