RT Journal Article A1 Xiaofang Liu,Chengcheng Hao,Lihua He,Cheng Yang,Yubin Chen,Chengbao Jiang,Ronghai Yu; AD Beihang University, 100191, 中国 ; Beihang University, 100191, 中国 ; Beihang University, 100191, 中国 ; Beijing Institute of Aeronautical Materials, 100095, 中国 ; Beijing Institute of Aeronautical Materials, 100095, 中国 ; Beijing Institute of Aeronautical Materials, 100095, 中国 ; Beihang University, 100191, 中国 ; Beihang University, 100191, 中国 T1 Yolk–shell structured Co-C/Void/Co9S8 composites with a tunable cavity for ultrabroadband and efficient low-frequency microwave absorption YR 2018 IS 8 vo 11 OP 4169-OP 4182 K1 microwave absorption;metal organic framework;yolk–shell structure;sulfide;broad bandwidth AB A yolk–shell structured Co-C/Void/Co9S8 ternary composite composed of a Co nanoparticle-embedded porous carbon core and Co9S8 shell was synthesized by the sulfidation of a Co-based zeolitic imidazolate framework and subsequent pyrolysis. The composition and interior cavity of the Co-C/Void/Co9S8 composite could be precisely modulated by controlling the sulfidation reaction. Due to the abundant heterointerfaces, well-controlled cavity, and magnetic–dielectric synergistic effects, the Co-C/Void/Co9S8 exhibited excellent and tunable microwave-absorbing properties. The optimized Co-C/Void/Co9S8, having a loading of 25 wt.% and thickness only 2.2 mm, displayed an ultrabroad absorption bandwidth of 8.2 GHz at high frequencies. Moreover, the composite could achieve an extremely high reflection loss of–54.02 dB at low frequencies by adjusting its loading to 30 wt.%. This study provides a new insight into promising lightweight microwave-absorbing materials with ultrabroad absorption bandwidths and strong low-frequency absorption. SN 1998-0124 LA EN