MS 2 ( M = Co and Ni) Hollow Spheres with Tunable Interiors for High- Performance Supercapacitors and Photovoltaics

We demonstrate in this paper facile synthesis of CoS2 and NiS2 hollow spheres with various interiors through a solution-based route. The obtained CoS2 microspheres constructed by nanosheets display a three-dimensional architecture with solid, yolk-shell, double-shell, and hollow interiors respectively, with continuous changes in specific surface areas and pore-size distributions. Especially, the CoS2 hollow spheres demonstrate excellent supercapacitive performance including high specific capacitance, good charge/discharge stability and long-term cycling life, owing to the greatly improved faradaic redox reaction and mass transfer. Furthermore, CoS2 hollow spheres exhibit superior electrocatalytic activity for disulfide/thiolate (T-2/T-) redox electrolyte in dye-sensitized solar cells (DSCs). Therefore, this work provides a promising approach for the design and synthesis of structure tunable materials with largely enhanced supercapacitor behavior, which can be potentially applied in energy storage devices.