Abstract: Doping with non-metallic elements represents a highly promising strategy for tailoring the dielectric properties of composite materials. Owing to its merits such as high structural stability and excellent process reproducibility, this approach has garnered significant attention in the field of electromagnetic wave absorption. In this study, tellurium doping was introduced into a Ni_xS₆@De composite with a hierarchical pore structure, inducing lattice distortion and creating abundant defects, thereby promoting the formation of interfacial dipoles. As a result, the obtained material exhibits outstanding absorption performance across microwave (achieving a minimum reflection loss of -43.54 dB at 1.7 mm thickness and an effective absorption bandwidth of 5.19 GHz), ultraviolet, and infrared spectra (with a low average reflectivity of ∼4 %). More importantly, the synergistically engineered defect configuration effectively impedes the penetration of corrosive species, enhances the electrochemical passivation effect, and simultaneously enables a 100 % sterilization inhibition rate against sulfate-reducing bacteria. Furthermore, the composite demonstrates remarkable thermal stability, maintaining performance above 300 °C, and exhibits anisotropic heat insulation properties. This multi-scale defect engineering paradigm offers a universal design strategy for developing advanced materials integrating efficient electromagnetic attenuation, corrosion resistance, antibacterial activity, and thermal variability.

Key words: Diatomite, Microwave absorption, Multi-function, Corrosion resistance, Antibacterial activity