J. Mater. Sci. Technol. ›› 2023, Vol. 148: 250-259.DOI: 10.1016/j.jmst.2022.12.003

• Research article • Previous Articles    

Morphology controllable urchin-shaped bimetallic nickel-cobalt oxide/carbon composites with enhanced electromagnetic wave absorption performance

Fushan Lia, Qiuyu Lia, Hideo Kimuraa, Xiubo Xiea, Xiaoyu Zhanga,b, Nannan Wuc, Xueqin Suna, Ben Bin Xud, Hassan Algadie,f, Rami Adel Pashameahg, Abdullah K. Alanazih, Eman Alzahranih, Handong Lii, Wei Dua,*, Zhanhu Guoi,j,**, Chuanxin Houa,*   

  1. aSchool of Environmental and Material Engineering, Yantai University, Yantai 264005, China;
    bShandong Laboratory of Yantai Advanced Materials and Green Manufacturing, Yantai 264005, China;
    cSchool of Material Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China;
    dMechanical and Construction Engineering, Faculty of Engineering and Environment, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK;
    eCollege of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China;
    fDepartment of Electrical Engineering, Faculty of Engineering, Najran University, Najran 11001, Saudi Arabia;
    gDepartment of Chemistry, Faculty of Applied Science, Umm Al-Qura University, Makkah 24230, Saudi Arabia;
    hDepartment of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia;
    iIntegrated Composites Laboratory (ICL), Mechanical and Construction Engineering, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK;
    jDepartment of Chemical and Bimolecular Engineering, University of Tennessee, Knoxville, TN 37996, United States
  • Received:2022-12-06 Revised:2022-12-22 Accepted:2022-12-22 Published:2023-06-10 Online:2023-06-05
  • Contact: **Corresponding author at: Integrated Composites Laboratory (ICL), Mechanical and Construction Engineering, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK. E-mail addresses:. zhanhu.guo@northumbria.ac.uk (Z. Guo); *duwei@ytu.edu.cn (W. Du), chuanxin210@ytu.edu.cn (C. Hou)

Abstract: The microscopic morphology of electromagnetic wave absorbers influences the multiple reflections of electromagnetic waves and impedance matching, determining the absorption properties. Herein, the urchin-shaped bimetallic nickel-cobalt oxide/carbon (NiCo2O4/C) composites are prepared via a hydrothermal route, whose absorption properties are investigated by different morphologies regulated by changing calcination temperature. A minimum reflection loss (RLmin) of -75.26 dB is achieved at a matching thickness of 1.5 mm, and the effective absorption bandwidth (EAB) of 8.96 GHz is achieved at 2 mm. Multi-advantages of the synthesized NiCo2O4/C composites contribute to satisfactory absorption properties. First, the interweaving of the needle-like structures increases the opportunities for scattering and multiple reflections of incident electromagnetic waves, and builds up a conductive network to facilitate the enhancement of conductive losses. Second, the carbon component in the NiCo2O4/C composites enhances the interfacial polarization and reduces the density of the absorber. Besides, generous oxygen vacancy defects are introduced into the NiCo2O4/C composites, which induces defect polarization and dipole polarization. In summary, the ternary coordination of components, defects and morphology led to outstanding electromagnetic wave absorption, which lightened the path for improving the electromagnetic wave absorption property and enriching the family of NiCo2O4 absorbers with excellent performance.

Key words: NiCo2O4/C, Oxygen vacancies, Interfacial polarization, Electromagnetic wave absorber