Preparation and characterization of carbon quantum dots grafted Co3O4 nanocomposite for supercapacitors application
P. Prabakaran, Gowdhaman Arumugam, Perumal Ramu, Manickam Selvaraj, Mohammed A. Assiri, Samuel Lalthazuala Rokhum, Periyasamy Sivakumar, Silambarasan Arjunan, R. Ramesh
Abstract
A pure Co 3 O 4 nanoparticles and a carbon quantum dots (CQDs) anchored cobalt oxide (Co 3 O 4 /CQD) nanocomposite were synthesized by a simple hydrothermal method for supercapacitor application. The powder XRD measurement confirms the formation cubic phase of Co 3 O 4 . More HR-TEM measurements. The beneficial surface and electronic properties of CQDs were used for the refinement of the electrochemical accomplishments of Co 3 O 4 . The Co 3 O 4 /CQD and Co 3 O 4 manifest half-cell specific capacitances of 193.8 F g −1 and 123.6 F g −1 @ current density of 4 A g −1 , respectively. The introduction of CQDs into the Co 3 O 4 matrix increased the charge-transfer process, which is primarily responsible for the improved electrochemical capabilities of the nanocomposite. The hybrid asymmetric supercapacitor delivers an energy density of 2.49 W h kg −1 @ a power density of 426 W kg −2 with a capacitance retention of 81.8%.