Symmetric supercapacitor devices based on pristine g-C3N4 mesoporous nanosheets with exceptional stability and wide operating voltage window

• Published in: Journal of energy storage Vol. 52; p. 104850
• Main Authors: Ghanem, Loujain G., Hamza, Mahmoud A., Taha, Manar M., Allam, Nageh K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2022
• Subjects: C3N4; Doping; High potential window; Stability; Symmetric supercapacitor; C3N4; Symmetric supercapacitor; Stability; High potential window; Doping
• ISSN: 2352-152X; 2352-1538
• DOI: 10.1016/j.est.2022.104850

We report a facile low-cost thermal polymerization method of urea to produce 2D carbon nitride nanosheets (GCN) as confirmed via a plethora of morphological and structural characterization techniques. The GCN electrodes showed excellent electrochemical performance with a very wide operating voltage window upon their use as positive and negative poles in supercapacitor devices. The GCN exhibited high specific capacitance as positive and negative electrodes in 0.5 M H2SO4. The symmetric supercapacitor (GCN//GCN) device possesses a wide operating voltage window of 2 V, with an ultrahigh energy density of 19.33 Wh/kg and superior stability over 21,000 charge/discharge cycles. The device was assembled on graphite sheet and not on Ni foam to avoid the raised caveats on the contribution of the redox-active Ni foam to the measured capacities. These unique properties can be ascribed to the high nitrogen doping level (exceeding 12%), revealing the potential of pristine GCN as promising candidates for further investigation and development in energy conversion and storage applications. [Display omitted] •Thermal polymerization method of urea produced 2D g-C3N4 nanosheets.•The g-C3N4 exhibited high specific capacitance as positive and negative electrodes.•The supercapacitor (GCN//GCN) device showed a wide operating voltage window of 2 V.•The (GCN//GCN) device revealed an ultrahigh energy density of 19.33 Wh/kg.•The device showed a superior stability over 21,000 charge/discharge cycles.