Exploration of cost-effective counter electrodes (CEs) has been a long-term objective for dye-sensitized solar cells (DSSCs). In the current work, binary Fe-Co nanofiber alloys are pioneerly synthesized by a low-temperature hydrothermal reduction approach and employed as CE materials for DSSCs. Owing to the rapid charge-transfer, electrical conduction, and electrocatalysis, the binary Fe-Co nanofiber alloy CE based DSSCs have reasonable power conversion efficiencies. An optimal efficiency of 5.06% is recorded from DSSC using FeCo2 nanofiber alloy CE. The relatively high conversion efficiency, low cost in combination with simple preparation, and scalable components demonstrates the potential use of Fe-Co alloy CEs in robust DSSCs. (C) 2014 Elsevier B.V. All rights reserved.