Tri-iodide reduction activity of ultra-small size PtFe nanoparticles supported nitrogen-doped graphene as counter electrode for dye-sensitized solar cell

Divya Nechiyil; B P Vinayan; S Ramaprabhu

doi:10.1016/j.jcis.2016.11.011

Tri-iodide reduction activity of ultra-small size PtFe nanoparticles supported nitrogen-doped graphene as counter electrode for dye-sensitized solar cell

J Colloid Interface Sci. 2017 Feb 15:488:309-316. doi: 10.1016/j.jcis.2016.11.011. Epub 2016 Nov 4.

Authors

Divya Nechiyil¹, B P Vinayan², S Ramaprabhu³

Affiliations

¹ Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India.
² Helmholtz Institute Ulm for Electrochemical Storage (HIU), Helmholtzstr. 11, D-89081 Ulm, Germany.
³ Alternative Energy and Nanotechnology Laboratory (AENL), Nano Functional Materials Technology Centre (NFMTC), Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India. Electronic address: ramp@iitm.ac.in.

PMID: 27838555
DOI: 10.1016/j.jcis.2016.11.011

Abstract

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^-/I₃^-) 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 (∼6.12%) with lower charge transfer resistance, which helps in faster diffusion of I^-/I₃^- 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.

Keywords: Counter electrode; DSSC; Electrocatalytic activity; Graphene; Power conversion efficiency.