Helical carbon nanofiber as a low-cost counter electrode for dye sensitized solar cells

Helical carbon nanofiber (HCNF) is prepared by the pyrolysis of acetylene using Cu nanoparticle catalyst and investigated as the low-cost counter electrode in dye-sensitized solar cells. The obtained HCNF sample displays a form of regular single nanocoil with the coil diameter of 50 nm and has a high surface area of 156 m(2) g(-1). The electrochemical measurements indicate that HCNF electrode possesses an excellent electrocatalytic activity for the reduction of I-3(-); the charge-transfer resistance of HCNF electrode is 1.1 Omega cm(2) in the I-/I-3(-) redox electrolyte. Under illumination of 100 mW cm(-2) (AM 1.5), the dye-sensitized solar cell based on HCNF counter electrode achieves an energy conversion efficiency of 6.74%, which is comparable to that of the device based on Pt counter electrode. (C) 2016 Elsevier B.V. All rights reserved.