Fabrication of N‑Doped Reduced Graphite Oxide/MnCo2O4 Nanocomposites for Enhanced Microwave Absorption Performance

• Published in: Langmuir 2021-02, Vol.37 (6), p.2213-2226
• Main Authors: Ghosh, Kalyan, Srivastava, Suneel Kumar
• Format: Article
• Language: English
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.0c03641

The present work reports on the fabrication of a lightweight microwave absorber comprising MnCo2O4 prepared from the urea complex of manganese (Mn)/cobalt (Co) and nitrogen-doped reduced graphite oxide (NRGO) by facile hydrothermal method followed by annealing process and characterized. The phase analysis, compositional, morphological, magnetic, and conductivity measurements indicated dispersion of paramagnetic MnCo2O4 spherical particles on the surface of NRGO. Our findings also showed that Mn, Co–urea complex, and GO in the weight ratio of 1:4 (NGMC3) exhibited maximum shielding efficiency in the range of 55–38 dB with absorption as an overall dominant shielding mechanism. The reflection loss of NGMC3 was found to be in the range of −90 to −77 dB with minima at −103 dB (at 2.9 GHz). Such outstanding electromagnetic wave absorption performance of NRGO/MnCo2O4 nanocomposite compared to several other metal cobaltates could be attributed to the formation of percolated network assisted electronic polarization, interfacial polarization and associated relaxation losses, conductance loss, dipole polarization and corresponding relaxation loss, impedance matching, and magnetic resonance to some extent.