Graphene-loaded porous ZnCo2O4 nanosheets composite as counter electrode for dye-sensitized solar cells

Graphene-loaded porous ZnCo2O4 nanosheets composite (ZnCo2O4/RGO) had been synthesized by annealing the precursors, which were obtained after a simple hydrothermal method. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) images revealed the microstructure of as-synthesized products. Raman spectroscopy confirmed the existence of RGO in the composite. ZnCo2O4/RGO composite exhibited great electrocatalytic property for reduction of I3−, which showed enormous enhancements than that of pure ZnCo2O4 and RGO. It can be ascribed to the synergetic effect between porous ZnCo2O4 nanosheets and RGO films. As counter electrode (CE) for dye-sensitized solar cells (DSSCs), ZnCo2O4/RGO composite gained power conversion efficiency (PCE) of 6.73%, which was up to 88% of that for Pt CE (7.69%).