Magnetic quantum dots modified hollow carbon spheres and controllable electromagnetic wave absorption performance

Carbon-based materials owing to their customizable dielectric loss and the light weight characteristic have become increasingly popular as microwave absorption materials. However, due to the weak loss property and the poor impedance matching, the absorbing performance especially the absorption bandwidth is not satisfactory. Herein, magnetic quantum dots modified hollow carbon microspheres were constructed through structural design, interface regulation and magnetization strategies. The hollow structure significantly facilitated the impedance matching and the reduction of weight. Synchronously, the introduction of the magnetic quantum dots endowed the composites with excellent magnetic response. As a result, the as-obtained composites delivered an effective absorption bandwidth of 6.6 GHz with a thickness of 2.4 mm. Moreover, the composites exhibited an ultra-wide effective absorption band of 8.0 GHz (10–18 GHz) with a matching thickness of 2.6 mm. Thus, the proposed strategy shed new lights on the design, synthesis, and performance regulation of lightweight broadband microwave absorption materials.