Construction of two-dimensional thick sheet-like carbide and Co nanocrystals heterostructure toward efficient electromagnetic wave absorption

Abstract

Deeply studied the electromagnetic wave absorption (EWA) mechanism of Mo2C heterostructure is crucial for realizing the application of Mo2C-based materials in new multifunctional integrated microwave absorbing coatings. In order to exclude the influence of special three-dimensional morphology (spherical, hollow, etc) on EWA performance, we designed the two-dimensional (2D) thick sheet-like Mo2C/Co@NC heterostructure that composed of molybdenum carbide (Mo2C), cobalt (Co) nanoparticles and nitrogen-doped carbon (NC), derived from the MoO42− substituted 2D sheet-like Co zeolite imidazolate frameworks (Mo/Co BIFs). The Mo2C/Co@NC has better EWA performance than Co@NC and Mo2C@NC. In the thickness range of 2∼4 mm, the effective absorption bandwidth can cover up to 10.5 GHz, and the strongest absorption can reach −48 dB. Behind the excellent EWA performance, multiple polarization relaxation and enhanced interface polarization are acting together. Moreover, the structure and interface effects of Mo2C/Co heterojunction are also revealed by DFT calculation. This work provides a workable methodology for manipulating the heterogeneous interface of MOFs-derived Mo2C based material and understanding the EWA mechanism of Mo2C-based heterostructure.