Study of NiO/CNSs hybrid nanostructure as an electrode material: synthesis and excellent electrochemical performance for application of supercapacitors

A hybrid nanostructure comprising nickel oxide nanoparticles and carbon nanospheres (NiO/CNSs), synthesized via wet chemical process is demonstrated as high-performance electrochemical supercapacitors. The resulting structure exposes that NiO/CNSs electrode possesses irregularly shaped nanoparticles. The NiO/CNSs hybrid nanostructure gives a smaller contact angle of 7 degrees for 6 M KOH electrolyte solution revealing better surface wettability, which enhances the transportation of electrolytic ions into the surface of the electrode material. Furthermore, oscillator strength of Raman active modes confirms the presence of disorder and lower degree of graphitization, which play an important role to improve the electrochemical performance. The NiO/CNSs electrode exhibits a high-specific capacitance of 1380 F g(-1) at a current density of 4 A g(-1) and long cycle life with 97% charge retention after 1000 cycles. These outcomes reveal that NiO/CNSs can be a promising electrode material for supercapacitors. Graphic abstract