Decoration of multi-walled carbon nanotubes with nickel oxide quantum dots for high-performance electrochemical supercapacitors

Abstract

Designing highly efficient and cost-effective energy storage systems, like supercapacitors, has been introduced as one of the most promising technologies for removing obstacles to clean energy utilization. Carbon-based materials with considerable electrochemical properties and chemical durability are good candidates to employ as electrodes for supercapacitor applications. Here, multi-walled carbon nanotubes (MWCNTs) were hydrothermally decorated with nickel oxide (NiO) quantum dots (QDs) and utilized as supercapacitor electrodes. The electrochemical properties of NiO@MWCNTs were considerably improved compared with the bare MWCNTs due to the boosted electrical conductivity and specific surface area. The synergy between NiO and MWCNTs increased the electrochemical performance of the NiO@MWCNTs electrode and recorded a particular capacity of 397.93 F.g⁻¹ at 1.0 A.g⁻¹. Notably, the NiO@MWCNTs electrode maintained 99.17 % of its initial specific capacity after 15,000 cycles at 1.0 A.g⁻¹. The results open paths for developing high-efficiency energy storage devices based on carbon-based materials.