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TiO2-based photocatalytic disinfection has been proved as one of the feasible approaches for the control and inhibition of the growth of mould fungi on woody materials. However, the wide band gap of TiO2 (3.2 eV) limits the efficient absorption of sunlight in the visible region. In this study, visible-light-mediated antifungal bamboo based on Fe-doped TiO2 thin films was successfully fabricated through a facile one-step homogeneous precipitation method. XRD studies confirmed that all of the as-prepared TiO2 nanoparticles on the bamboo surface were anatase phase. Fe-doped TiO2 thin films were found to grow on the bamboo surface by the self-aggregation of nanoparticles with an average diameter of about 9.7 nm and a surface area of about 90.96 m2 g−1. The Fe-doped TiO2/bamboo samples looked identical to original bamboo as there was no essential effect on the optical properties of the bamboo surface. Moreover, the antifungal activity of the as-prepared samples against mould fungi was investigated under natural weather conditions. Compared with original bamboo and TiO2/bamboo, the Fe-doped TiO2/bamboo exhibited much higher inhibition ability to mould fungi under the natural environment, which is due to the fact of the red shift of the absorption edge of the Fe-doped TiO2 nanostructures on the bamboo surface. UV-vis DRS also revealed that the band gap of Fe-doped TiO2 nanostructures was obviously decreased, extending the light response of TiO2 from ultraviolet to the visible light region. The research result may provide a general and effective approach to prepare visible-light-driven photocatalysts used for inhibition of the growth of mould fungi on the surface of bamboo.

Heat treatment is an excellent method of improving the properties of wood. Study of the physical and chemical changes of lignin during heat treatment is essential for expanding the application areas based on new properties. In this study, we investigated the degradation behavior of enzymatic hydrolysis lignin (EHL) heat treated at different temperatures (180 °C, 200 °C, and 220 °C) and for different durations (2 h and 4 h). The optical property changes of EHL before and after heat treatment were investigated by measuring color and UV-Vis absorbance changes. Fourier transform infrared spectroscopy (FTIR) was used to characterize the chemical modifications resulting from heat treatment. Mass spectrometry (MS) was used to elucidate the variation of the mass-to-charge (m/z) ratios of ions produced by EHL during heat treatment. These experimental results indicate that both the EHL mass loss percentages and chromatic aberration exhibited an increase with increasing temperature and duration of heat treatment. In contrast, the UV-Vis absorbance, most of the FTIR absorption peaks, and the m/z values of EHL showed a decreasing trend. It was found that the color change of lignin was not the major cause of wood discoloration during heat treatment. The better resistance of the heat treated wood toward solar radiation was attributed to the lower UV absorption of post-treatment lignin.