NiCo2S4 nanosheets on 3D wood-derived carbon for microwave absorption.

• 3D NiCo 2 S 4 /C hybrid composites were successfully constructed for the first time. • The optimal RL of NiCo 2 S 4 /C reaches −64.74 dB with the maximum EAB of 5.26 GHz. • The enhancement is attributed to the matched impedance and improved loss ability. • The attenuation mechanism was discussed according to the characterization results. Advanced electromagnetic wave (EMW) absorbing materials with low-cost, lightweight, high absorption efficiency and wide absorption frequency are extremely desirable for solving electromagnetic radiation. Herein, an excellent microwave absorber composed of NiCo 2 S 4 nanosheets decorated three-dimensional (3D) hierarchically porous carbon derived from biomass was successfully designed and constructed via a facile strategy for the first time. The results shown that the morphology and EMW absorption ability of 3D NiCo 2 S 4 /C hybrid composites could be synchronously tailored just by controlling the initial content of cetyltrimethyl ammonium bromide (CTAB) as a surfactant, and a substantial enhancement of microwave absorption performance could be achieved after the introduction of NiCo 2 S 4 nanosheets, resulting from the matched impedance and the enhanced attenuation constant. The optimized NiCo 2 S 4 /C composites exhibit strong EMW absorption abilities, whose minimum reflection loss (RL min) value reaches −64.74 dB with an ultra-thin thickness of 1.91 mm, and the effective absorption bandwidth (EAB, RL ≤ − 10 dB) is up to 5.26 GHz ranging from 9.22 to 14.48 GHz, which could also cover the entire X-band within 2.23–2.31 mm thickness. This work provides a new sight to design and prepare next-generation microwave absorbers with high absorption efficiency and wide absorption frequency through a low-cost, sustainable and effective method. [ABSTRACT FROM AUTHOR]