N-doped bagasse-derived carbon/Pt composite (NBC/Pt) with a very low Pt loading (0.31 wt%) is synthesized by a simple and ecofriendly hydrothermal process with bagasse as the carbon precursor and investigated as the counter electrode (CE) of dye-sensitized solar cells (DSSCs). The N doping reduces Pt nanoparticles size and facilitates the dispersion of Pt nanoparticles, which promotes the strong interaction between Pt and carbon supports. The electrochemical results show that the structural feature is beneficial to improve charge transfer rate on the interface between Pt nanoparticles and carbon supports, resulting in the enhanced catalytic activity toward I-/I-3(-) redox couples. Under simulated AM 1.5 G solar illumination at 100 mW cm(-2), the DSSCs with the NBC/Pt composite CE exhibit a 6.98% power conversion efficiency (PCE), which is superior to the conventional Pt (PCE = 6.08%) CE. The NBC/Pt composite is an attractive CE material that can use 2.52 x less Pt loading onto each FTO substrate than the conventional Pt CE, which is advantageous over the high cost Pt for the fabrication of DSSCs. (C) The Author(s) 2017. Published by ECS. All rights reserved.