Novel porous FexCyNz/N-doped CNT nanocomposites with excellent bifunctions for catalyzing oxygen reduction reaction and absorbing electromagnetic wave

Pea-like Fe/Fe3C Nanoparticles Embedded in Nitrogen-Doped Carbon Nanotubes with Tunable Dielectric/Magnetic Loss and Efficient Electromagnetic Absorption

“…Similar functions of one-dimensional microstructure were also identified in Ni nanofibers, Co/CoO nanofibers, and MoO 2 /C nanowires. − These facts greatly promote the development of one-dimensional magnetic carbon-based composites as high-performance MAMs, thanks to the positive combination of functional and structural advantages. , A popular strategy is to decorate some carbon substances, for example, carbon nanotubes (CNTs) and carbon nanofibers, with different magnetic components, while such magnetic carbon-based composites easily suffer from insufficient loading and serious agglomeration of magnetic particles, resulting in poor chemical homogeneity and degraded microwave absorption performance . The embedment of magnetic particles inside CNTs may be a desirable configuration to restrain their agglomeration. , More importantly, Che et al ever pointed out that when magnetic metal Fe was confined inside CNTs, the involved multiple domain wall displacements along the axial direction of CNTs would consolidate natural magnetic resonance and magnetic loss effectively . It is unfortunate that the loading of abundant magnetic particles inside CNTs cannot be achieved easily.…”

“…This unique configuration will be significantly helpful to improve the microwave absorption performance of these composites, as it not only provides sufficient heterogeneous interfaces between Fe-based nano- particles and carbon components but also restrains the formation of Fe-based conductive networks that may account for strong reflection toward incident EM waves and reduce magnetic loss through possible skin effect. 38,43 Figure 3 shows XRD patterns of Fe/Fe 3 C@NCNTs obtained at different pyrolysis temperature. As observed, there are no any characteristic diffraction peaks that can be indexed to metal iron or iron oxides in Fe/Fe 3 C@NCNTs-500, indicating that the carbothermal reduction of Fe 3+ has not been triggered under such conditions.…”

“…Therefore, the specific microstructure of these pea-like composites can be depicted as core–shell nanoparticles with Fe-based nanoparticles and graphitic carbon coating embedded inside graphitic NCNTs. This unique configuration will be significantly helpful to improve the microwave absorption performance of these composites, as it not only provides sufficient heterogeneous interfaces between Fe-based nanoparticles and carbon components but also restrains the formation of Fe-based conductive networks that may account for strong reflection toward incident EM waves and reduce magnetic loss through possible skin effect. , …”

“…36 The embedment of magnetic particles inside CNTs may be a desirable configuration to restrain their agglomeration. 37,38 More importantly, Che et al ever pointed out that when magnetic metal Fe was confined inside CNTs, the involved multiple domain wall displacements along the axial direction of CNTs would consolidate natural magnetic resonance and magnetic loss effectively. 39 It is unfortunate that the loading of abundant magnetic particles inside CNTs cannot be achieved easily.…”

Tuning Dielectric Loss of SiO2@CNTs for Electromagnetic Wave Absorption

“…Thus, the SiO2@Fe3C/Fe@NCNT-GT showed a significantly enhanced EMW absorption property in the main parameters, including RL, min, EAB10 and d values, showing it has potential applications in practical EMW absorption. In addition, our prepared SiO2@Fe3C/Fe@NCNT-GT had comparable, or better, EMW absorption performance than reported carbon nanotube-based absorbent materials (Figure 5c, Table S2) [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]. The Mz-f plot reveals that the SiO2@Fe3C/Fe@NCNT-GT had better impedance matching characteristics compared to the SiO2@Fe3C/Fe@NCNT (Figure S9).…”