▎ 摘　　要

Efficient and cost effective counter electrode (CE) is pre-requisite for the commercialization of dye sensitized solar cell (DSSC). Present work investigates ultra small size platinum-iron alloy nanoparticles dispersed over nitrogen-doped graphene (PtFe/NG) as an effective counter electrode for DSSC. Hereby we achieve low loading of Pt by alloying with Fe accompanied by superior electrocatalytic activity towards the iodide-triiodide (I-/I-3(-)) mechanism. Enhancement in electrocatalytic performance of PtFe/NG has been shown by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization analysis. PtFe/NG counter electrode exhibits higher power conversion efficiency (similar to 6.12%) with lower charge transfer resistance, which helps in faster diffusion of ions as compared to NG and Pt/NG counter electrodes. The increased electrocatalytic activity of PtFe/NG is due to the collective effect of intrinsic electronic effects by alloying, uniform dispersion of small PtFe alloy nanoparticles over nitrogen doped graphene, and additional catalytic sites offered by nitrogen-doped graphene. (C) 2016 Elsevier Inc. All rights reserved.