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[Display omitted] Microwave absorption materials can protect humanity from harmful electromagnetic radiation, but it is still a challenge to absorb electromagnetic radiation with different bands simultaneously. Herein, an effective strategy for obtaining WSe 2 @CNTs nanohybrids is reported. The conductive network and polarization of WSe 2 @CNTs nanohybrids can be tailored by confinedly implanting WSe 2 nanosheets on multi-walled carbon nanotubes. The electromagnetic properties and microwave absorption performance of the nanohybrids are effectively adjusted via changing the hybrid ratio of WSe 2 and CNTs. Multi-band microwave absorption is achieved with up to three bands. The reflection loss (RL) of the sample can reach −60.1 dB, and the bandwidth can reach 4.24 GHz (RL ≤ −10 dB). The excellent microwave absorption performance is attributed to the conductance and multiple relaxations, as well as the synergistic effect of the two. This result confirms that WSe 2 @CNTs nanohybrids are potential candidates for high-efficiency microwave absorbers and provide a valuable pathway for designing high-performance microwave absorption materials in the future. [ABSTRACT FROM AUTHOR]

• WSe 2 @CNTs/Co 3 O 4 with tunable electromagnetic properties was constructed. • Excellent microwave absorption was demonstrated. • Multi-band microwave absorption with three absorption bands was achieved. • The synergistic effect of dielectric and magnetic loss was revealed. The ideal electromagnetic (EM) absorption material requires high efficiency, broadband absorption, lightweight and multi-band absorption. Conventional dielectric materials have limitations in microwave absorption due to the single attenuation mechanism. Introducing magnetic materials is an effective strategy to improve the microwave attenuation capability of absorbers. In this work, the novel ternary WSe 2 @CNTs/Co 3 O 4 nanocomposites with efficient multi-band EM absorption capabilities were fabricated, its minimum reflection loss (RL) can reach up to −54.09 dB and the effective bandwidth (BW) of RL < −10 dB can reach 4.64 GHz. Meanwhile, the BW can be effectively tuned by optimizing the content of Co 3 O 4 and thickness of absorbers to achieve multiband absorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • WSe 2 @CNTs heterojunction with highly efficient wave absorption was constructed. • WSe 2 @CNTs heterojunction has green EMI shielding function. • The mechanism of tunable EM properties for dual EM functions was revealed. CNTs, with high electrical conductivity, are considered as an excellent electromagnetic (EM) attenuation material, and have attracted the attention of countless researchers for a long time. However, there is a daunting challenge to obtain both microwave absorbing and electromagnetic interference (EMI) shielding functions in a same material. Herein, by constructing WSe 2 @CNTs heterojunction, excellent microwave absorbing and EMI shielding is obtained, which is attributed to the tunable dielectric properties. The WSe 2 @CNTs composite shows high reflection loss (RL) of −61.6 dB, broad effective absorption bandwidth (EAB) of 4.56 GHz, and efficient EMI shielding. More importantly, high green shielding index (>1) is found in the Ku band. This result confirms the WSe 2 @CNTs composite as a suitable candidate for EM bifunctional materials. Meanwhile, this strategy of constructing heterojunction provides a valuable guide for designing novel EM attenuation materials in the future. [ABSTRACT FROM AUTHOR]