In this study, carbide-metal composite coatings (WC-10Co4Cr) were prepared via high-velocity oxygen-fuel (HVOF) spraying, and the influence of Mo₂C addition on the microstructure, mechanical properties, and wear performance was systematically investigated. The results indicate that Mo₂C is solid-soluted in WC during the preparation process, which induces lattice distortion. Mo₂C addition results in refinement of the grain size of WC particles, homogenization of the binder phase distribution, and reduction of the porosity of the coatings. An appropriate amount of Mo₂C addition significantly enhances coating performance. The coating containing 2 wt.% Mo₂C exhibited optimal properties. It demonstrated the highest microhardness and the lowest porosity, and wear tests revealed it had the lowest friction coefficient and wear rate at room temperature, which is primarily due to enhanced hardness and density that effectively suppressed abrasive wear. At 400 °C, the coating with 2 wt.% Mo₂C addition also showed the most stable and lowest friction coefficient. The generated Mo-containing oxides acts as a solid lubricant, isolating friction surfaces and mitigating both oxidative and adhesive wear. However, excessive Mo₂C content leads to an abnormal increase in the volume fraction of the binder phase, accompanied by reduced hardness. This induces a transition of the wear mechanism toward adhesive wear dominance, with complex nonlinear evolution characteristics.

Current antibacterial sprays face major limitations, including rapid evaporation, short-lived efficacy, skin irritation, and poor adhesion to surfaces, highlighting an urgent need for a durable and biocompatible alternative. To address these challenges, we developed a ZIF-8-based spray (ZNS-WO20) composed of ZIF-8 nanoparticles dispersed in 50% ethanol and 20% OTES. OTES acts as a dispersant and binder, enabling wash-resistant coatings on gauze and glass. ZIF-8 exhibits pH-responsive Zn²⁺ release, achieving nearly 100% killing of S. aureus, E. coli, and methicillin-resistant S. aureus (MRSA) at 160 μg/mL through intracellular reactive oxygen species (ROS) generation. The spray maintains >95% antibacterial efficacy against S. aureus after five washing cycles and seven days of outdoor exposure, and causes no dermal irritation in rats. This work fills the gap for a long-lasting, skin-friendly antibacterial spray, showing promise for healthcare disinfection and surface protection.