Etching engineering and electrostatic self-assembly of N-doped MXene/hollow Co-ZIF hybrids for high-performance microwave absorbers

Exploring high-performance microwave absorbing materials with lightweight, thin thickness and strong electromagnetic wave (EMW) absorption capability is an essential way to solve EMW pollution problems. Herein, layered N-doped MXene (Ti3CNTx) flakes and hollow Co-ZIF particles (HCF) hybrids were successfully fabricated using the controllable cooperative protection etching strategy and the electrostatic self-assembly technology. Remarkably, the microwave absorption hybrids achieved ultrathin (1.43 mm), and strong EMW absorption ability (reflection loss of −55.02 dB) with a rather low filler loading, which is superior to the magnetic–dielectric hybrids with similar components reported in the literatures. The synergistic effect generated by the improvement of dielectric loss, magnetic loss and interface polarization could effectively integrate with the impedance matching to improve the attenuation ability of EMW. Therefore, this simple assembly and etching strategy opens a new platform for designing hollow and layered materials and broadens the desirable candidates for lightweight and high-efficient microwave absorbers.