ZnO Low-Dimensional Thin Films Used as a Potential Material for Water Treatment ^†

Abstract

In this work, the properties of zinc oxide (ZnO) low-dimensional conductive oxide nanostructures in the aspect of their potential applications in microelectronics, in toxic gas sensing, as well as in water remediation, have been determined. ZnO nanostructured porous thin films deposited by DC reactive sputtering (RS) have been deposited on Si substrates at different temperature conditions. For surface properties and chemical morphology analysis, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) have been used. Thanks to these techniques, it was possible to obtain information on thin film surface modifications caused by the adsorption of atmospheric carbon dioxide, and by the adsorption of photodegradation products following the photocatalysis experiments. The ZnO thin films were tested for their photocatalytic properties under UV light irradiation. For this purpose, methylene blue was used as a dye model pollutant to evaluate the activity of the nanostructures. It was observed that the ZnO thin films are able to photocatalytically degrade methylene blue. These results demonstrate that properly selected zinc oxide nanostructures, currently used in toxic gas sensing, can find application in the removal of micropollutants such as dyes and pharmaceuticals present in wastewater.