Core-shell structured Ag@SiO2 microspheres: A promising candidate for electromagnetic absorption

The rapid advancement of social information substantially expands the application range of electromagnetic technology and leads to a significant increase in electromagnetic wave pollution. In this study, silver ions undergo sensitization, activation, and subsequent reduction processes, the silver shell is formed on SiO 2 matrix. Microstructure, morphology, and electromagnetic wave absorption performance of as-prepared Ag@SiO 2 and SiO 2 were explored. When the Ag content reaches 10 wt%, the shells achieve a dense coating on the matrix. The results demonstrate that the Ag@SiO 2 (10 wt%) composite achieves a remarkable reflection loss of −52.48 dB and an absorption bandwidth of 2 GHz, at an absorber thickness of 5.3 mm and a frequency of 4.96 GHz. Compared to the reflection loss of −2.5 dB exhibited by SiO 2 , it showcases excellent electromagnetic wave absorption capability. Such significantly enhanced absorption capability of Ag@SiO 2 composites can be attributed to local surface plasmon resonance behavior induced at the interface. This study elucidates the electromagnetic wave absorption mechanism of the Ag@SiO 2 composite and successfully demonstrates its potential as a high-performance composite for electromagnetic wave absorption. Consequently, it provides a feasible solution to address the challenges associated with electromagnetic pollution.