Morphology-controlled growth of NiCo2O4 ternary oxides and their application in dye-sensitized solar cells as counter electrodes

Abstract

In this article, ternary oxides NiCo2O4 with morphologies of nanosheets, nanorods and nanoflowers have been synthesized by the thermal treatment of the precursors which were fabricated via a hydrothermal process. The materials were then used as counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). The DSSCs equipped with NiCo2O4 nanoflowers CE achieved excellent power conversion efficiency (PCE) of 8.48%, which is higher than that of counter parts of NiCo2O4 nanosheets (3.57%), NiCo2O4 nanorods (6.84%) and Pt (8.11%) CEs. Transmission electron microscopy image shows that the NiCo2O4 nanoflowers have the best porous 3-dimensional spatialstructure. This study offers a self-assembled synthetic route to prepare NiCo2O4 nanoflowers. The unique structure exhibits high efficient performance and excellent catalytic activity, which may open a new window to use ternary oxides for greatly extending potential applications in dye-sensitized solar cells and other related fields.