Comprehensive studies of the hydrothermal growth of ZnO nanocrystals on the surface of bamboo

To determine the hydrothermal growth conditions for ZnO nanocrystals on the surface of bamboo and to further develop new ZnO/bamboo hybrid materials, ZnO nanostructured materials with six morphologies, namely, spheroidal nanoparticles, nanoparticles, nanoneedles, nanograsses, nanowall networks, and nanoorchids, were successfully grown on the surface of bamboo via a low-temperature hydrothermal method based on sol–gel-prepared ZnO seed layers. The effects of temperature, time, molar ratio (zinc acetate/sodium hydroxide), and zinc salt precursor (zinc nitrate, zinc sulfate, zinc chloride, and zinc acetylacetonate) on the ZnO morphologies were comprehensively studied. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and energy dispersive spectrometry (EDS) were employed to characterize the morphology, chemical structure, and crystalline structure of the ZnO nanomaterials deposited on the bamboo surface. The ZnO nanostructure morphology was most sensitive to temperature and could be controlled by the reaction temperature. All of the as-prepared ZnO nanostructured materials were wurtzite. ZnO nanomaterials were bonded through the interaction between the hydroxyl moiety of the bamboo surface and the corresponding ZnO. A possible hydrothermal fabrication mechanism was also proposed. Further research is required to assess the improvements in the properties of bamboo from the hydrothermal deposition of nanomaterials at the bamboo surface.