Implanting Ag nanoparticles in SiOC ceramic nanospheres for exceptional electromagnetic wave absorption and antibacterial performance

The development of multifunctional composites with desired electromagnetic wave absorption and antibacterial performance for the medical field has aroused wide concern. In this work, SiOC/Ag composites were successfully fabricated via liquid phase method. When the filler content of SiOC/Ag-3 is 40 wt.%, SiOC/Ag-3 exhibits excellent electromagnetic wave absorption performance, achieving a minimum reflection loss value of -58.03 dB with a matching thickness of only 2.82 mm. The superior electromagnetic wave absorption performance is attributed to multiple reflections, conductive loss and interfacial polarization loss. Besides, the RCS simulation indicates all RCS values of PEC with SiOC/Ag-3 coating are below -20 dB·m² across the incident angle range from -60 ° to 60 °, exhibiting strong radar stealth performance. Moreover, SiOC/Ag composites also achieve excellent antibacterial ability to <em>E. coli</em> and <em>S.aureus</em> by reactive oxygen species under visible light radiation. This work provides new insights into the design and development of bifunctional composites with electromagnetic wave absorption and antibacterial performance for application in medical devices.