The composites of g-C3N4 and conductive carbon black (CCB) were prepared by a simple ball-milling process and explored as the counter electrode for dye-sensitized solar cells (DSCs). The enhanced electrocatalytic activity for I-3(-) reduction can be demonstrated when CCB was incorporated into g-C3N4. The charge-transfer resistance of g-C3N4/CCB (1:1, mass ratio) composite electrode was 2.4 Omega cm(2), which is much lower than those of the individual g-C3N4 and CCB electrodes, indicating predominant synergistic effect of g-C3N4 and CCB in electrocatalytic activity. Under illumination of 100 mW cm(-2), the DSC with g-C3N4/CCB (1:1) composite counter electrode achieved a conversion efficiency of 5.09%, which is comparable to that of the cell with Pt counter electrode. (C) 2016 Elsevier Ltd. All rights reserved.