Magnetron Sputtered ZnO Enhances Light-Aging Resistance of Heat-Treated 'Zhongshanshan' Wood

Abstract 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 enhance certain 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 heat-treated Taxodium hybrid 'Zhongshanshan' wood via magnetron sputtering to improve its resistance to light-induced aging. Results revealed that the ZnO coating was uniformly deposited with well-defined crystallinity and did not compromise the visibility of the wood’s natural texture. The optimal modification effect was achieved under 120 minutes of sputtering. The initial water contact angle increased to 139.5° prior to light aging. After exposure, the color difference (ΔE) was 3.63, and the contact angle remained relatively high at 122.8°. 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.