Crystal phase control synthesis of metallic 1T-WS2 nanosheets incorporating single walled carbon nanotubes to construct superior microwave absorber

Two-dimensional transition metal dichalcogenides (TMDs) have attracted tremendous attentions due to their unique properties, and the development of phase control technique brings out new opportunities in emerging application fields. In this work, tungsten disulfide (WS2) nanosheets containing 1T phase predominately were incorporated with single walled carbon nanotubes (SWCNTs) through a facial hydrothermal method. Two-dimensional flexible and ultrathin WS2 nanosheets were in situ grown on one-dimensional SWCNTs bundles, further forming typical urchin-like microsphere with diameters distributing in the range of 2-3 mu m uniformly. Accordingly, dielectric loss could be significantly enhanced due to the strong interface coupling effect between WS2 nanosheets and SWCNTs bundles, which induced considerable electrical conductivity and abundant capacitor-like structures. Consequently, the minimum reflection loss (RL) could reach up to -66 dB at 8.3 GHz with a matching thickness of 2.2 mm. Furthermore, RL values lower than -10 dB could be attained in the range of 3.0-18.0 GHz with integrated thicknesses from 5.0 to 1.0 mm. Prospectively, our present work may provide new opportunity to design TMDs based composites by means of crystal phase control technique as lightweight and high-performance microwave absorbers. (C) 2019 Elsevier B.V. All rights reserved.