Doping Strategy to Boost the Electromagnetic Wave Attenuation Ability of Hollow Carbon Spheres at Elevated Temperatures

Currently, the electromagnetic (EM) wave absorbers usually suffer severe performance degradation when they work for a while due to the generated heat issue. Developing a high-performance EM absorber with flexibility and adjustability that can effectively absorb the EM energy and convert into thermal energy at elevated temperature is highly desired but still remains a significant challenge. Herein, we demonstrate S-doped hollow carbon nanospheres used as fillers to fabricate a flexible and controllable EM absorber toward this challenge. Owing to the insertion of S-based polar groups in the graphitization area of carbon spheres, this EM absorber exhibits outstanding electromagnetic wave absorption capability with elimination of X-band EM wave performance at a temperature range of 298-423 K. Almost 90% of the X-band EM wave can be dissipated at 373 K, while the effective absorption rate of 75% can still be achieved at 423 K.