Cobalt diselenide (CoSe2) is endowed with excellent and stable photoelectrochemical properties. However, the preparations of CoSe2 usually need high pressure, high temperature, long reaction time or special devices. Here, CoSe2 counter electrodes are prepared by a facile electrochemical deposition method and controlling different deposition voltage. The influence of deposition voltage on the film quality and the performance of dye-sensitized solar cells is investigated, and the CoSe2 counter electrode with -1.1 V deposition voltage achieve a best power conversion efficiency of 10.17%, which has a 21.9% increase compared to the solar cell based on platinum counter electrode (8.35%). The impressive efficiency together with facile preparation highlights the potential for substitute for the noble metal platinum. (C) 2017 Elsevier Ltd. All rights reserved.