Nano assembly of N-doped graphene quantum dots anchored Fe3O4/halloysite nanotubes for high performance supercapacitor

• Published in: Electrochimica acta Vol. 245; pp. 912 - 923
• Main Authors: Ganganboina, Akhilesh Babu, Chowdhury, Ankan Dutta, Doong, Ruey-an
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 10.08.2017
• Subjects: capacitor; energy density; fabrication; Fe3O4; halloysite; power density; Fe3O4; power density; energy density; halloysite; fabrication; capacitor
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2017.06.002

[Display omitted] •Halloysite coated Fe3O4 is served as the framework for supporting graphene quantum dots.•GQDs can be well distributed onto Fe3O4/HNTs to prevent structural failure.•High specific capacitance of 418Fg−1 in 1M Na2SO4 neutral electrolyte is observed.•The composites show excellent electrochemical performance with energy density of 10.4–29.0 Wh kg−1. The development of robust and low cost electrode materials with superior electrochemical properties has been a subject of focus on energy storage devices. Herein, the development of N-doped graphene quantum dots (N-GQDs) deposited on Fe3O4-halloysite nanotubes (Fe3O4-HNTs) as active anode materials has been established for supercapacitor applications. The Fe3O4 nanoparticles synthesised by coprecipitation have been in-situ deposited on HNT surfaces following by the coating of (3-aminopropyl)-triexthoxysilane to anchor 4–10nm N-GQDs via the formation of amide linkage. The N-GQD@Fe3O4-HNTs exhibits a high specific capacitance of 418Fg−1 and maintains good rate capability in neutral electrolyte solutions. In addition, the anode materials show excellent electrochemical performance with energy and power densities of 10.4–29W h kg−1 and 0.25–5.2kWkg−1, respectively. Such excellent electrochemical features can be attributed to the synergistic contribution from individual components. The Fe3O4-HNTs provide 1-dimensional matrix to shorten the diffusion path of electrons and electrolyte ions as well as to absorb the mechanical stress during cycling along with excess sites for charge storage, while N-GQDs offer abundantly accessible electroactive sites for rapid electrons and electrolyte ions transport as well as enhance electrical conductivity of Fe3O4-HNTs. Results obtained in this study clearly demonstrate that metal oxide-HNTs are promising support to anchor N-GQDs nanomaterials as the high performance anode materials for next generation of energy storage devices with high energy and power densities.