Improved mould resistance and antibacterial activity of bamboo coated with ZnO/graphene

Abstract

Bamboo is susceptible to mould and attack by fungi because of its high content of starch and sugar. To make bamboo-based outdoor materials, a new type of bamboo timber with improved mould resistance and antibacterial activity, coated with reduced graphene oxide and nanocrystal ZnO (abbreviated as RGO@ZnOBT), was fabricated by a two-step dip-dry and hydrothermal process. A possible synthesis mechanism for RGO@ZnOBT was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscope, energy-dispersal X-ray analysis, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. According to the China standard test method, the <i>Aspergillus niger</i> mould resistance of RGO@ZnOBT is grade 2, whereas the <i>Trichoderma viride</i> and <i>Penicillium citrinum</i> mould resistance of RGO@ZnOBT is grade 0, both of which are better than the grade 4 of original bamboo timber. The <i>Escherichia coli</i> resistance test showed that the antibacterial circle of RGO@ZnOBT is 3 mm, which is significantly higher than that of original bamboo timber (0 mm). The antibacterial activity of treated bamboo is significantly improved compared with that of untreated bamboo.