Photocatalytic degradation of organic dyes using ZnO nanorods supported by stainless steel wire mesh deposited by one-step method

Abstract

In this work, a sol-gel method was used to deposit Al-doped ZnO coatings on stainless steel wire meshes. The effect of coating thickness on the morphology evolution and the photoluminescence, photocatalytic properties were investigated. Field emission scanning electron microscope (FE-SEM) observed that when the Al-doped ZnO coating was thin, it was composed of many nanoparticles. However, with the increase of the coating thickness, some sparse nanorods appeared on the ZnO coating surface. When the coating thickness was increased to six layers, the areal density of nanorods was largely increased. X-ray diffraction (XRD) patterns revealed that the ZnO coatings crystallized into a wurtzite structure, and the nanorods were preferentially oriented along the c-axis direction. Photoluminescence spectra showed that after ZnO nanorods were formed, the UV emission of ZnO coatings was significantly enhanced, which meant that the nanorods had better crystal quality than the nanoparticles. The photocatalytic performance tests for these samples showed that the sample formed by six layers of ZnO sol had the best photocatalytic activity due to its high crystalline quality and the large specific surface area. These ZnO coatings loaded on stainless steel wire meshes exhibited good photocatalytic stability.