3D Ultralight Hollow NiCo Compound@MXene Composites for Tunable and High-E cient Microwave Absorption

The 3D hollow hierarchi-cal architectures tend to be designed for inhibiting stack of MXene flakes to obtain satisfactory lightweight,high-e cient and broadband absorbers.Herein,the hollow NiCo compound@MXene networks were prepared by etching the ZIF 67 template and subsequently anchoring the Ti_(3)C_(2)Tx nanosheets through electrostatic self-assembly.The electromagnetic parameters and microwave absorption property can be distinctly or slightly regulated by adjusting the filler loading and decoration of Ti_(3)C_(2)Tx nanoflakes.Based on the synergistic e ectsof multi-components and special well-constructed structure,NiCo layered double hydroxides@Ti_(3)C_(2)Tx(LDHT-9)absorber remarkably achieves unexpected e ective absorption bandwidth(EAB)of 6.72 GHz with a thickness of 2.10 mm,covering the entire Ku-band.After calcination,transition metal oxide@Ti_(3)C_(2)Tx(TMOT-21)absorber near the percolation threshold possesses minimum reflection loss(RLmin)value of-67.22 dB at 1.70 mm within a filler loading of only 5 wt%.This work enlightens a simple strategy for constructing MXene-based composites to achieve high-e cient microwave absorbents with lightweight and tunable EAB.

Ultrathin self-assembly MXene/Co-based bimetallic oxide heterostructures as superior and modulated microwave absorber

Lightweight and high-efficiency absorbing materials equipped with tunable electromagnetic properties are the foremost important factors for driving applications of 5 G smart era and military stealth.Stim-ulated by the remarkable merits of heterogeneous interface engineering,a series of unique flower-like Co-based multiphases nanostructures were successfully synthesized through identical hydrothermal method,and subsequently anchored on the Ti_(3)C_(2)T_(x)nanosheets.The suitable metal ion modulation is feasible to regulate the components,heterogeneous interfaces and defects for tailoring the electromag-netic parameters and microwave absorption(MA)property.Notably,the permittivity decreases of CMOT(CoO/MCo_(2)O_(4)/Ti_(3)C_(2)T_(x),M=Fe,Cu,Zn)composites proceed gradually in the order of Fe^(2+),Cu^(2+),Zn^(2+),while the MA performance with tunable absorption peak could be modulated subtly.The asobtained CFOT-12(10 wt%),CCOT-15(10 wt%)and CZOT-15(15 wt%)exhibit excellent MA capacity with a minimum reflection loss(RL_(min))of-41.06,-52.67,-52.52 dB and corresponding effective absorption bandwidth(EAB)of 3.68,4.48,3.92 GHz at 2.10,1.90,1.80 mm,respectively.This work expands a novel approach to construct multicomponent heterostructure for tuning the EM parameters and absorbing property,as well as realize the high efficient and light weight.