Magnetron sputtered ZnO enhances light-aging resistance of heat-treated ‘Zhongshanshan’ wood

With the growing utilization of fast-growing timber in the wood industry, issues such as poor dimensional stability and low durability have become increasingly prominent. Although heat treatment can improve those wood properties, the material remains susceptible to photodegradation under prolonged ultraviolet (UV) exposure, which limits its applicability in outdoor environments. In this study, ZnO was deposited onto the surface of heat-treated Taxodium hybrid ‘Zhongshanshan’ wood via magnetron sputtering to improve its resistance to light-aging. Results revealed that the ZnO coating was uniformly deposited with well-defined crystallinity and it did not compromise the visibility of the wood’s natural texture. After sputtering for 120 min, the light-aging resistance of heat-treated wood improved significantly. For example, the color difference (ΔE) decreased by about 50% as compared to the uncoated wood after light aging. By the way, the coating also can improve the waterproofing of wood surface, such as the initial water contact angle only decreased from 139.5° to 122.8° after light aging. Comprehensive characterization by SEM, XPS, EPR, and UV-Vis demonstrated that the ZnO coating inhibited the formation of free radicals and surface oxidation, thereby enhancing the wood’s resistance to UV-induced photodegradation. These findings highlight the effectiveness of magnetron sputtering as a physical modification approach for improving the long-term weathering performance of heat-treated fast-growing wood.