▎ 摘　　要

Nitrogen doped graphenes (NGs) were synthesized by pyrolysis of graphene polypyrrole composites (G-PPys) for application as counter electrode (CE) in dye sensitized solar cells (DSSCs). The as-prepared NGs demonstrate mesoporous texture with large specific surface areas, high N doping level with homogeneous distribution, as well as moderate graphitization phase, all of these structural and interfacial features are beneficial for abundant active sites and well conductivity, therefore can effectively promote the electrocatalytic reduction of I-3(-) and improve the photovoltaic performances of pertinent DSSC5. The optimized sample, denoted as NG2, used as CE of DSSC exhibit high power conversion efficiency (PCE) (6.8%) with high reliability and durability, which is comparable to that of Pt CE (7.0%). Given the cost effective synthesis and the high electrochemical performance, NG2 herein is a promising non-Pt CE alternative material in DSSC. (C) 2015 Elsevier Ltd. All rights reserved.