Flower-like CoS hierarchitectures@polyaniline organic-inorganic heterostructured composites: Preparation and enhanced microwave absorption performance

Although the heterostructured composites with micro/nanostructure have already been studied as potential microwave absorbers, it still remains a great challenge to achieve strong absorption and wide absorbing bandwidths. Herein, flower-like CoS hierarchitectures@polyaniline (PANI) organic-inorganic heterostructured composites were fabricated by a facile solvothermal approach and oxidative polymerization process. The incorporation of PANI into flower-like CoS microspheres not only improves the impedance matching, produces multiple reflections and scatterings, and causes conduction loss derived from PANI, but also creates more interfacial and dipolar polarizations, which results in increased dielectric loss. And more importantly, the synergy of CoS and PANI further improves the electromagnetic (EM) wave absorbing ability. Compared with the pristine CoS and PANI, the heterogeneous CoS@PANI composites demonstrate a strong EM absorption property with an optimal reflection loss (RL) of -54.1 dB at 11.4 GHz, and wide effective absorption bandwidth (EAB) of 5.3 GHz (RL < -10 dB) is obtained at the thickness of 2.5 mm. Moreover, an ultra-wide EAB achieves 13.3 GHz covering from 4.7 to 18 GHz and minimal RL values all are less than -20 dB with tunable thickness ranging from 2.0 mm to 5.0 mm. The work reveals that constructing an organic-inorganic hierarchical heterostructure would be an ideal approach to develop novel microwave absorbers with excellent microwave absorbing properties.