Growth of ZnO nanofilms on wood with improved photostability

Abstract

A major drawback of wood in outdoor exposure is photodegradation of the surface. Nano zinc oxide (ZnO) has been reported to provide enhanced stability of wood against UV degradation. In this study, the formation of ZnO nanostructures on the surface of solid wood was achieved via a simple two-step process consisting of generation of ZnO seeds on the wood surface followed by a solution treatment to promote crystal growth. The morphology and chemical composition of the ZnO films was studied by field-emission scanning electron microscopy combined with energy dispersive X-ray and X-ray diffraction. Accelerated weathering was used to evaluate the photostability of treated wood. The morphology of ZnO nanofilm was dependent on the exposure time in the ZnO seeding solution. Greatly enhanced photostability was achieved with treated wood. UV stability was partially dependent on crystal morphology. This two-step method could probably also be employed to treat other biomaterials with rough surfaces such as bamboo.