A bilayer carbon coated Ni3S2 composite nanowall (carbon/Ni3S2) film was first used as a counter electrode for a dye-sensitized solar cell (DSSC). The carbon/Ni3S2 film was synthesized by a chemical bath deposition and an arc evaporation process. A DSSC with Ni3S2 composite counter electrode exhibited an efficiency of 8.40%, which slightly exceeded that of a Pt (8.38 %). Moreover, bilayer carbon/Ni3S2 nanowall further increased photovoltaic conversion efficiency to 9.64 %. Such dramatic improvement of solar efficiency using a Pt-free composite made of carbon/Ni3S2 nanowall was due to the large surface area of the nano structure and their good co-electrocatalytic activity. (C) 2015 Elsevier Ltd. All rights reserved.