Facile Synthesis of Znco2o4@Nimoo4 with Porous Coated Structures on Carbon Paper as Stable and Efficient Pt-Free Counter Electrode Materials for Advanced Liquid Film Solar Cells

Abstract

A porous coating structure transition metal oxide ZnCo2O4@NiMoO4 composite was successfully synthesized on the surface of carbon paper (CP) by a simple two-step hydrothermal method as a Pt-free material for counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). ZnCo2O4 grows uniformly on the surface of CP to form porous structure, and then NiMoO4 is wrapped on the surface of ZnCo2O4 to form a nanoscale composite system. The composite materials shows remarkable electrocatalytic performance in reducing iodine electrolyte and improving the photoelectric conversion efficiency (PCE) of DSSCs, which is due to the synergistic catalytic effect of transition metal oxides distributed on the surface of CP and the conductivity provided by carbon material. Therefore, the DSSCs equipped with ZnCo2O4@NiMoO4/CP material CEs achieves a PCE of 9.30% (with Jsc is 20.51 mA·cm-2, Voc is 0.763 V, FF is 0.60), which is much higher than that of Pt CEs (7.36%) under the same light conditions, and also higher than that of ZnCo2O4/CP, NiMoO4/CP grown on CP alone and pure CP under the same conditions.

Keywords: porous coating structure, Pt-free, counter electrodes, electrocatalytic, dye-sensitized solar cells