Synergistic effects of dopants on the spin density of catalytic active centres of N-doped fluorinated graphene for oxygen reduction reaction

Progress in many electrochemical energy technologies relies on the efficiency of their catalysts. Prohibitively high cost of conventional metal catalysts demands the search for metal-free catalysts in modern energy technologies. Herein we report multiple elements (nitrogen (N) and fluorine (F)) doped graphene - NFG as an efficient electrocatalyst, developed in bulk using a two-step wet chemical route. The NFG obtained in this work showed enhanced electrocatalytic efficiency than the 'N' and 'F' individually doped graphene, benchmarked electrocatalyst - Pt/C and other reported doped graphene systems. A density functional theory based approach has been employed to understand the synergistic doping effects of 'N' and in graphene, and the role of 'electron spin density' in determining the catalytic efficiency of graphene. This study opens up the possibilities of designing doped graphene based electrocatalysts by the 'mix and match' of various heteroatoms towards new and efficient energy technologies. (C) 2015 Elsevier Ltd. All rights reserved.