Multifunctional Ni–Co Nanozyme Composite with Synergistic Antibacterial and Flame-Retardant Properties

Multifunctional surface coatings with both antibacterial and flame-retardant properties are of great significance for enhancing the safety in critical applications. Herein, we report the development of a Ni–Co nanozyme-based composite coating that exhibits synergistic antibacterial and flame-retardant performance. The incorporation of dual-metal active sites within a hierarchical nanowire architecture endows the NiCo₂S₄ nanozyme with a mechano-catalytic antibacterial mechanism, enabling efficient and broad-spectrum bacterial inhibition. Additionally, the Ni–Co components facilitate the formation of a compact, highly graphitized char layer during combustion, serving as an effective physical barrier against heat and oxygen. As a result, the coating achieved a 23.6% reduction in the peak heat release rate (PHRR) while maintaining outstanding antibacterial performance. This work presents a promising strategy for the rational design of multifunctional composite coatings via nanozyme integration that meets the urgent need for advanced protection materials in safety-critical environments.