Gelatin-derived N-doped hybrid carbon nanospheres with an adjustable porous structure for enhanced electromagnetic wave absorption

Eco-friendly biomass-derived absorbers with high electromagnetic wave (EMW) absorbing property are ideal substitutes for traditional carbon absorber coming from non-renewable fossil energy. Based on this, a kind of novel gelatin-derived N-doped hybrid carbon nanospheres with adjustable porous structure (PGCNs) was fabricated successfully in this work by a simple desolvation method and following alkaline-activation process. By assembling precursor macromolecule to endow carbon absorber with unique tailored structure, the unstable EMW absorption performance caused by the unreproducible morphologies of most natural biomass precursors can be well avoided. Moreover, the developed porous structure on PGCNs could be tuned by changing the alkaline addition, following by the optimization of EMW absorbing performance. When loaded with 15 wt.%, the minimum reflection coefficient (RC_min) of PGCNs could reach as low as −58.03 dB at the thickness of merely 1.9 mm. The effective absorption bandwidth (EAB) was up to 6.3 GHz at the thickness of 2.2 mm. This work puts forward a new inspiration for designing repeatable structure for biomass-derived carbonaceous materials, and we believe that the as-fabricated PGCNs could be potential candidates in future EMW absorbing application. Graphical abstract: Gelatin-derived porous carbon nanospheres (PGCNs) were prepared firstly by desolvation and alkaline-activation process. The obtained PGCNs with highly porous structure and hybrid composition exhibited superior electromagnetic wave absorbing property such as a minimum reflection coefficient of -58.03 dB and an effective bandwidth of 6.3 GHz at the thickness of only 2.2 mm. [Figure not available: see fulltext.]