Direct growth of Ni3S2/MoS2 nanospheres on hierarchical nickel foam: A binder-free electrode architecture for next generation asymmetric supercapacitors and non-enzymatic glucose sensors

The cyclic life, rate performance, specific energy, and electrochemical sensing of electrode materials can be enhanced by tuning their nanostructures and compositions. Herein, the chemical vapor deposition technique was used to make direct deposition of MoS 2 nanosheets and Ni 3 S 2 /MoS 2 nanospheres on hierarchical nickel foam. The evaporated Ni 3 S 2 and MoS 2 achieved different energies, resulting in their different growth of diffraction planes with different peak intensities. The nanosheets and nanospheres were deposited successfully, which could render good surface area ∼50 m 2 g −1 , 128 m 2 g −1 , and pore ∼6.25 nm and 25 nm, respectively. The deposited MoS 2 and Ni 3 S 2 /MoS 2 electrodes provided a commendable capacitance of 1045 Fg −1 and 1828 Fg −1 at 1 Ag −1 , good cyclic life retaining 73% and 89% of their initial capacitance after 10,000 cycles with columbic efficiency of 85% and 98%. Besides, the asymmetric supercapacitor disclosed outstanding capacitance of 943 Fg −1 , specific energy of 297 Whkg −1 , with specific power of 2100 Wkg −1 at 3.5 Ag −1 and cyclic stability retaining 89.14% after 10,000 cycles at 35 Ag −1 . In electrolytic glucose oxidation, the Ni 3 S 2 /MoS 2 electrode also exhibited diffusion process contributions of ∼98–95% to the overall response at 5–30 mVs −1 , with surface process contributions of ∼2–5%.