Carbon aerogel microspheres with in-situ mineralized TiO₂ for efficient microwave absorption

Carbon aerogels (CAs) have been considered potential microwave absorption (MA) materials because of intrinsic hierarchical porous structure, low density, and excellent heat resistance. However, CAs always required to be ground into micron-scale powder before being used as microwave absorbers, which will inevitably destroy the hierarchical porous structure. Meanwhile, reproducing the optimized CAs powders is difficult. Herein, CAs microspheres with in-situ mineralized TiO₂ were easily prepared via a sol-gel transition and calcination process. The uniform size of CA microspheres and the loaded TiO₂ on the skeleton of CA yield great microwave attenuation performance while guaranteeing good impedance matching performance. The obtained TiO₂/CA hybrid presented a minimum reflection loss value of −30.2 dB and a broad effective absorption bandwidth (reflection loss below −10 dB) of 6.2 GHz. The low density, MA performance, and controllable particle size make the novel TiO₂/CA hybrid promising candidates for MA applications. [Figure not available: see fulltext.]