Rationally regulating complex dielectric parameters of mesoporous carbon hollow spheres to carry out efficient microwave absorption

In this study, the mesoporous carbon hollow spheres (MCHS) have been prepared through a facile hard-template etching strategy. It is confirmed that the tetrapropoxysilane (TPOS) has distinct influence on the dispersity, hollow cavity and shell thickness of MCHS. Furthermore, MCHS with different construction can regulate dielectric and microwave absorption effectively. We also proved that the generated hollow void and mesporous lay in carbon spheres could boost dielectric loss ability and impedance match behavior. When the addition of TPOS is 1.73 mL, the high specific surface area of MCHS can be achieved, in addition, the maximum reflection loss value of -50.9 dB at 11.1 GHz with a thickness of 3.2 mm can be gained. Moreover, corresponding effective bandwidth can be reached to 5.4 GHz ranging from 9.1 to 14.5 GHz. Besides, MCHS prepared by 3.46 mL TPOS can achieve broad bandwidth of 6.5 GHz (from 11.2 to 17.7 GHz) under 2.0 mm. The excellent microwave absorption capability of MCHS can be ascribed to the strong dielectric loss, hollow void and mesoporous in carbon shell, which were beneficial to the reflection and absorption of the microwave. Such light and efficient absorbers may be as predominant candidate for the applied in microwave absorption territory. (C) 2017 Elsevier Ltd. All rights reserved.