Versatile bimetal sulfides nanoparticles-embedded N-doped hierarchical carbonaceous aerogels (N-NixSy/CoxSy@C) for excellent supercapacitors and microwave absorption

The development of versatile functional composites is an intriguing and challenging approach to clean energy storage devices and electromagnetic pollution remediation. Herein, versatile bimetal sulfides nanoparticles-embedded N-doped 3D hierarchical carbonaceous aerogels was rationally constructed via controllable oxidation polymerization, mechanical blending and heat treatment methods. The encapsulation of bimetal NixSy/CoxSy nanoparticles and defects induced by N-doping can endow the fabricated aerogels with versatilities for excellent supercapacitors and microwave absorber. The dispersed and abundant active sites and easily diffused framework leads to remarkable electrochemical performances with a high specific capacitance of 2653.3 F g(-1) at 1 A g(-1) and excellent cycling stability of 89.2% at 10 A g(-1) over 5000 cycles. More importantly, the assembled asymmetric supercapacitor of N-Ni(x)Sy/Co(x)Sy@C-900//AC displayed an energy density of 98.9 W h kg(-1) at a power density of 371 W k g(-1). Moreover, taking advantage of the unique heterostructures and well impedance matching, as-fabricated composites exhibited outstanding microwave absorption performance. The minimum reflection loss (RL) of - 47.2 dB was achieved at 11.6 GHz with the thickness of 2.5 mm, and an effective frequency bandwidth (RL<-10 dB) could be gained up to 3.7 (9.8-13.5) GHz. This work presents potential application in supercapacitor and microwave absorption. (C) 2021 Elsevier Ltd. All rights reserved.