Multifunctional mixed valence N-doped CNT@MFe2O4 hybrid nanomaterials: from engineered one-pot coprecipitation to application in energy storage paper supercapacitors. Issue 26 (27th June 2018)

• Record Type: Journal Article
• Authors: Pereira, Clara; Costa, Rui S.; Lopes, Laury; Bachiller-Baeza, Belén; Rodríguez-Ramos, Inmaculada; Guerrero-Ruiz, Antonio; Tavares, Pedro B.; Freire, Cristina; Pereira, André M.
• Is Part Of: Nanoscale. Volume 10:Issue 26(2018)
• Page Start: 12820
• Page End: 12840
• Publication Date: 2018-06-27
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c8nr03533d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : N-doped CNT@MFe2 O4 hybrid nanomaterials were prepared by a highly controlled one-pot co-precipitation, leading to enhanced energy storage in paper supercapacitors. Abstract : This work reports on the design of novel mixed valence hybrid N-doped carbon nanotubes/metal ferrite nanomaterials (MFe2 O4, M(ii ) = Mn, Fe, Co) with tailored composition, and magnetic and electrical properties through a straightforward eco-sustainable and less time consuming one-pot in situ coprecipitation process. The potentialities of this strategy rely on the lack of oxidative treatments to the support and thermal annealing, besides the use of aqueous conditions, a chelating base (isopropanolamine) and low temperatures. The process afforded the controlled nucleation/growth of the MFe2 O4 nanoparticles (NPs), with sizes of 3.2–5.4 nm and superparamagnetic properties, on the surface of the N-doped carbon nanotubes (CNT-N) and their immobilization by covalent bonding. The nitrogen-based functionalities of CNT-N allied with the use of a coprecipitation agent with coordinating properties towards M(ii )/Fe(iii ) cations were responsible for these achievements. To unravel the potentialities of the novel nanohybrids (CNT-N@M), they were tested as electrode active nanomaterials in the fabrication of all-solid-state asymmetric paper supercapacitors (SCs). All asymmetric SCs presented significantly higher performance than the symmetric CNT-N based one, with an enhancement of the energy density to up to 6.0× and of the power density to up to 4.3× due to the occurrence of both non-faradaic and faradaic charge storage mechanisms. Moreover, they led to enhanced volumetric energy density (up to 11.1×) and power density (up to 5.2×) compared with other solid-state hybrid paper SCs based on carbon materials recently reported in the literature. These results highlight the importance of conjugating a conductive support bearing N-based functionalities with MFe2 O4 NPs featuring redox properties towards synergistically enhanced energy storage.