Lightweight, Low-Cost CoSiO@diatomite Core-Shell Composite Material for High-Efficiency Microwave Absorption.

The porous and biomimetic cobalt silicate@diatomite (CoSiO@diatomite) was successfully synthesized by a two-step method, including the hydrothermal method and calcination to improve the electromagnetic wave absorption property. Different hydrothermal times were well-tuned for CoSiO@diatomite composites with different loadings of CoSiO. Interestingly, the CoSiO@diatomite composites (6 h, 25 wt%) had a smaller minimum reflection loss. Moreover, the minimum reflection loss (RL) could reach -12.03 dB at 16.64 GHz and the matched absorber thickness was 10 mm, while the effective absorption bandwidth (EAB, RL ≤ -10 dB) could be 1.92 GHz. In principle, such findings indicate that CoSiO@diatomite nanocomposites could be a promising candidate for high-efficiency microwave absorption capability.