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Nowadays, electromagnetic pollution caused by the development of communication technology and electronic equipment has become an urgent problem to be solved. It is an effective solution to design high-performance electromagnetic wave absorption (EWA) materials with wide-band and powerful absorption characteristics for electromagnetic protection. In this work, a multi-scale MXene/carbon nanotube@Fe 3 O 4 composite material with a heterogeneous structure was synthesized by a solvothermal method, and the high/low-frequency EWA operating bands were adjusted by component regulation. The composite material performed excellent EWA performances based on the synergistic effect of polarization loss, conductive and magnetic loss, and three-dimensional heterointerfaces. Its minimum reflection loss reached − 59.95 dB with an effective absorption bandwidth of 4.7 GHz (13.3–18 GHz), which basically covered the Ku band. Therefore, this feasible scheme is expected to provide an effective strategy for controlling military and civil electromagnetic pollution. [Display omitted] • A facile preparation method of MXene-based multiscale composites was proposed. • Military/civil EWA operating frequency bands were adjusted by component regulation. • A superior RL min value of − 59.95 dB was obtained based on complex loss mechanisms. [ABSTRACT FROM AUTHOR]

The absorption performance of broadband electromagnetic waves is of utmost importance in safeguarding diverse electronic equipment against electromagnetic wave pollution, necessitating materials with low density, thin thickness, and cost-effectiveness to be employed. This study presents the successful synthesis of biomass-derived carbon (BC) composites via the hydrothermal method, utilizing moss coated with flower-like CuS. The CuS was uniformly dispersed on BC matrix, contribute to dipole polarization relaxation. The formation of heterogeneous interfaces between CuS and the BC phase resulted in significant polarization loss. Additionally, the wrinkled BC and flower like CuS constructed by nanosheets boosted scattering of electromagnetic wave due to its large specific surface area, which can provide additional channels for charge transfer and avail dissipation of electromagnetic wave energy. With an efficient absorption bandwidth (EAB) that encompasses the whole X band, the electromagnetic waves absorption (EMA) performance of CuS/BC composites was able to reach a minimum reflection loss of − 28.8 dB. • A simple preparation method of biomass-derived carbon (BC) composites was proposed. • The wrinkled BC and flower like CuS boosted scattering of electromagnetic wave. • The CuS/BC composites reached a superior minimum reflection loss of − 28.8 dB. [ABSTRACT FROM AUTHOR]

With the increasingly serious electromagnetic pollution, the urgent demands for electromagnetic wave absorption (EMWA) materials are gradually developing towards performance integration and multi-dimensional scales. Herein, the enoki-like carbon nanotubes (CNTs) coated with nickel particles (CNT@Ni) were synthesized by a catalytic thermal decomposition method. The resulting CNT@Ni composites exhibited excellent EMWA performances with a minimum reflection loss value of − 60.4 dB at a thickness of 2.97 mm. It benefited from the synergy of collaborative electrical and magnetic losses and hierarchical structure. The conductive pathways formed by the intertwined CNTs greatly improved the EMWA capacity of the material, enabling large amounts of electromagnetic waves to enter the material for conversion and dissipation. In addition, the inherent graphite defects and oxygen-containing groups formed on the material surface during the process of high-temperature treatment provided polarization centers for dipole polarizations. More importantly, the abundant heterogeneous interfaces enhanced the interface loss effects of the material. This simple preparation strategy of the CNT-based EMWA material will provide a design inspiration for the novel electromagnetic absorber. [Display omitted] • A simple preparation method of CNTs coated with nickel particles was proposed. • Enoki-like structures provided rich heterogeneous interfaces. • A superior RL min value of − 60.4 dB was obtained based on complex loss mechanisms. [ABSTRACT FROM AUTHOR]