Enhanced Electrocatalytic Activity by RGO/MWCNTs/NiO Counter Electrode for Dye-sensitized Solar Cells

We applied the reduced graphene oxide/multi-walled carbon nanotubes/nickel oxide (RGO/MWCNTs/NiO) nanocomposite as the counter electrode (CE) in dye-sensitized solar cells (DSSCs) on fluorine-doped tin oxide substrates by blade doctor method. Power conversion efficiency (PCE) of 8.13 % was achieved for this DSSCs device, which is higher than that of DSSCs devices using NiO, RGO, and RGO/NiO-CE (PCE = 2.71 %, PCE = 6.77 % and PCE = 7.63 %). Also, the fill factor of the DSSCs devices using the RGO/MWCNTs/NiO-CE was better than that of other CEs. The electron transfer measurement of cyclic voltammetry and electrochemical impedance spectroscopy showed that RGO/MWCNTs/NiO film could provide fast electron transfer between the CE and the electrolyte, and high electrocatalytic activity for the reduction of triiodide in a CE based on RGO/MWCNTs/NiO in a DSSC.