LAUSR

Abstract NiCo2S4 is an important multifunctional semiconductor that offers excellent electrochemical properties in a variety of applications such as dye-sensitized solar cells and supercapacitors. In this work, the dual application of porous hierarchical NiCo2S4 tremella-like nanostructures in energy harvesting and storage (dye-sensitized solar cells (DSSCs) and supercapacitors (SCs) respectively) is explored. In contrast to NiS nanosheets, CoS nanosheets and Pt counter electrodes (CEs), the tremelliform NiCo2S4 nanosheets CE demonstrated the lowest charge transfer resistance and highest electrocatalytic activity for the I3− reduction. The NiCo2S4-based DSSC showed higher power conversion efficiency (8.9%) even than that of Pt-based DSSC (8.6%) under simulated standard global AM 1.5G sunlight (100 mW cm−2). As an electrode material for SCs, the assembled NiCo2S4//AC asymmetric supercapacitor showed excellent specific capacitance (150.9 F g−1 at 1 A g−1), high energy density of 53.6 Wh kg−1 (with a power density of 799.8 W kg−1), and superior cycling durability with 88.3% retention after 5000 cycles at 2 A g−1.