Cu:ZnO deposited on porous ceramic substrates by a simple thermal method for photocatalytic application

Abstract

Thin films of undoped zinc oxide (ZnO) and doped ZnO with copper were deposited on ceramic pellets made from abundant local clay materials with an addition of zirconia (ZrO2). The thin layers were prepared by a thermal method using an autoclave. The resulting structural and morphological properties of the products were studied in order to determine the effectiveness of their photocatalytic activities. X-ray diffraction, Scanning Electron Microscopy, energy-dispersive X-ray spectroscopy and UV-visible spectrophotometry were used in this goal. An application test was carried out to quantify the photocatalytic degradation of a toxic organic dye – Orange II (OII) by these samples under UV light. In similar conditions, the layers deposited on the ceramics with addition of zirconia have shown better performances than those without zirconia. This result can be related to the porosity created when the zirconium oxide reacted with SiO2 of the clay. The open porosity observed on this type of substrate allows a larger surface for the photocatalysis. The degradation rate of OII reached 90.5% during a period of 7 h with Cu doped ZnO thin layers deposited on porous substrates modified with addition of ZrO2.