The optimization of hydrothermal process of MoS2 nanosheets and their good microwave absorption performances

In this study, flower-like MoS2 constructed by nanosheets was synthesized by a simple hydrothermal method. The hydrothermal process was optimized and the effects of hydrothermal condition, including reaction temperature, reaction time and the ratio of Mo source to S source (Mo:S) in precursor, on microwave absorption performances and dielectric properties were investigated. Our results showed that when the reaction temperature was 180 degrees C, the reaction time was 18 h, and the Mo:S was 1:3.5, the synthesized MoS2 had the best performance: Its minimum reflection loss could reach -55.78 dB, and the corresponding matching thickness was 2.30 mm with a wide effective bandwidth of 5.17 GHz. Further researches on the microwave absorption mechanism revealed that in addition to the destructive interference of electromagnetic waves, various polarization phenomena such as defect dipole polarization were the main reasons for microwave loss. We believe that MoS2 is a candidate for a practical microwave absorbent. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.