Nanostructured Co3O4/nitrogen doped carbon nanotube composites for high-performance supercapacitors

•Fabrication of fiber-like Co3O4/N-MWCNT composite.•Composite showed higher capacitance of 406 F g-1 at a current density of 2 A g−1.•Excellent cyclic stability and reversibility.

In this study, a nanostructured cobalt oxide/nitrogen doped multiwall carbon nanotube (N-MWCNT/Co3O4) composite was synthesized by thermal decomposition process in the presence of aqueous ammonia and urea. Transmission electron microscopy (TEM) confirmed that the nanostructured Co3O4 nanoparticles were densely decorated over the N-MWCNT surface. The supercapacitive properties of the composite electrode were studied in aqueous potassium hydroxide (KOH). The composite showed high specific capacitance (406 F g−1 at a current density of 2 A g−1) and excellent cycle stability (93% capacitance retention after 10,000 cycles), demonstrating its potential application in high-performance supercapacitors.