摘要
A novel type of three-dimensional ultralight aerogel sphere,consisting of one-dimensional nanocellulose-derived carbon fibers and two-dimensional graphene layers,was prepared based on a developed drop-freeze-drying followed by carbonization approach.The nanofibrous carbon efficiently prevents the agglomeration of the graphene layers,which,in turn,reduces the shrinkage and maintains the structural stability of the hybrid carbon aerogel spheres.Consequently,the aerogel spheres showing an ultralow-density of 2.8 mg/cm^(3) and a porosity of 99.98%accomplish the tunable dielectric property and electromagnetic wave(EMW)absorption performance.The high-efficiency utilization of biomass-derived fibrous nanocarbon,graphene,the porous structure of the hybrid aerogel spheres leads to the excellent EMW absorption performance.The aerogel spheres display an effective absorption bandwidth of 6.16 GHz and a minimum reflection loss of−70.44 dB even at a filler loading of merely 3 wt.%,significantly outperforming that of other biomass-derived carbon-based EMW absorbing materials.This work offers a feasible,facile,scalable approach for fabricating high-performance and sustainable biomass-based aerogels,suggesting a tremendous application potential in EMW absorption and aerospace.
基金
the National Key R&D Program of China(No.2021YFB3502500)
the Natural Science Foundation of Shandong Province(Nos.2022HYYQ-014 and ZR2016BM16)
the New 20 Funded Programs for universities of Jinan(No.2021GXRC036)
the Provincial Key Research and Development Program of Shandong(Nos.2019JZZY010312 and 2021ZLGX01)
the National Natural Science Foundation of China(No.22205131)
the Natural Science Foundation of Jiangsu Province(No.BK20220274)
the Shenzhen Municipal Special Fund for Guiding Local Scientific and Technological Development(No.2021Szvup071)
the Joint Laboratory project of Electromagnetic Structure Technology(No.637-2022-70-F-037)
the Qilu Young Scholar Program of Shandong University(No.31370082163127).