Facile synthesis of lightweight 3D hierarchical NiCo2O4 nanoflowers/reduced graphene oxide composite

• 作 者: Ning Sun Wen Li Shuang Wei Hui Gao Wei Wang Shougang Chen
• 机 构: School of Materials Science & Engineering,Ocean University of China,Qingdao,266100,China
• 出 处: 材料科学技术（英文版）
• 发表日期: 2021年32期
• 关键词: NiCo2O4 nanoflowers Reduced graphene oxide foam Lightweight Low filling ratio Br

Considering the high filling ratios,high densities,and narrow absorbing bandwidths of the current elec-tromagnetic wave (EMW) absorbers,in this work,we successfully synthesized a 3D hierarchical NiCo2O4 nanoflowers/reduced graphene oxide (NiCo2O4/RGO) composite foam by a simple method under gentle condition.The NiCo2O4 nanoflowers and unique 3D foam structure are beneficial to the refraction and scattering of EMW,which endows the prepared 3D foam with highly efficient EMW absorption perfor-mance.When the ratio between NiCo2O4 and RGO in the foam is 1∶1,5％ mass fraction of NiCo2O4/RGO foam in paraffin wax can reach a minimum reflection loss (RLmin) value of-52.2 dB with a thin thick-ness merely 2.6 mm.Simultaneously,the effective absorption bandwidth (EAB,RL exceeding-10 dB) is 7.04 GHz that covers the whole Ku band (10.96-18 GHz).Moreover,the effects of the thickness of the absorber and the loading ratios of the foam in paraffin wax matrix on the EMW absorption propetties are also carefully investigated.The results indicate that the optimum EMW absorption performance of NiCo204/RGO can be tuned in different bands.The EMW absorption mechanism is ascribed to the proper impedance matching and larger dielectric and magnetic loss produced by the synergy of NiCo2O4 and RGO.Therefore,the NiCo2O4/RGO hybrid foam is ideal candidate to be used as high-efficient EMW ab-sorbers with low filling ratio,light weight,and broad frequency bandwidths.