Abstract
NiCo nanoparticles(NPs)-doped carbon nanofibers were synthesized by calcination of electrospun nanofibers composed of nickel acetate, cobalt acetate and poly(vinyl alcohol) in argon atmosphere and used as an efficient and alternative Pt-free electrocatalyst as counter electrode materials for dyesensitized solar cells (DSSCs). Structural and electrochemical properties of the NiCo NPs-doped carbon nanofibers counter-electrodes were inspected by field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), andelectrochemical impedance spectroscopy (EIS). This Pt-free counter electrode shows high catalytic activity, surface area and conductivity. Moreover, more catalytic active sites for the reduction reaction at the electrolyte/counter electrode interface and strong contact between the film and FTO substrate have been observed. Therefore, the DSSCs based on NiCo (NPs) carbon nanofibers counter exhibits an enhanced photovoltaic conversion efficiency of 4.47%. As the result, the introduced nanofibers can be considered as a promising counter electrode for DSSCs. (C) 2015 Elsevier Ltd. All rights reserved.