Co0.85Se hollow nanoparticles as Pt-free counter electrode materials for dye-sensitized solar cells

In this paper, Co0.85Se hollow nanoparticles have been successfully synthesized by a one-step solvothermal method. The Co0.85Se counter electrode (Co0.85Se CE) has been fabricated and used for dye-sensitized solar cells (DSSCs). The electrocatalytic activity of CEs has been characterized by cyclic voltammetry, Tafel-polarization curves, and electrochemical impedance spectroscopy. The results indicate that Co0.85Se CE with a large surface area shows the high electrocatalytic activity for the reduction of I-3(-). The power conversion efficiency of the DSSC based on Co0.85Se CE is obtained up to 6.03%, which is slightly lower than that of the DSSC based on Pt CE (6.45%). (C) 2015 Elsevier B.V. All rights reserved.