Low-frequency microwave absorption poses an important challenge due to the excessive thickness of absorbers, which inherently correlates with wavelength. Herein, Bi2Te3 nanosheets were synthesized via a solvothermal method to achieve high permittivity, aiming to address the issue of low-frequency microwave absorption. The as-prepared nanosheets demonstrate a tunable ultra-high permittivity (up to 282) at 2 GHz, accompanied by a loss tangent below 0.81 and pronounced frequency dispersion characteristics. The nanosheet material demonstrates a synergistic balance of ultrahigh permittivity and appropriate dielectric loss, attributed to its surface-state-conducting and bulk-insulating character. At 2.4 GHz, the composite material composed of Bi2Te3 nanosheet achieves an effective absorption with an electrical thickness of 0.032, which is significantly thinner than those reported for state-of-the-art microwave absorbing materials. By leveraging the high permittivity and pronounced frequency dispersion characteristics of Bi2Te3 nanosheet composites, broadband microwave absorption is achieved across both 2- to 6-GHz and 6- to 18-GHz ranges through multilayered architectures. This work provides a strategic approach to overcome the longstanding challenge of broadband low-frequency microwave absorption.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |