Effect of Thickness on Photocatalytic Properties of ZnO thin films Deposited by RF Magnetron Sputtering

Autor: Zulema Rebollar Rivera, Maria de la Luz Olvera Amador, Arturo Maldonado Álvarez
Rok vydání: 2019
Předmět:
Zdroj: CCE
Popis: Zinc oxide (ZnO) thin films were deposited on soda lime glass substrates by using the RF magnetron sputtering technique. The deposition process was carried out in a system initially evacuated at $\pmb{7x10}^{-\pmb{5}}$ torr and a working pressure of 10−3 torr in a pure argon atmosphere, at room temperature. A 2“ diameter and $\pmb{1}/\pmb{4}$ ” thick ZnO target (99.999%) was used. A target-substrate distance of 10 cm, and a working power of 125 W were kept constant. The films were deposited at different thicknesses, 50 to 400 nm. The thickness, the optical, structural and morphological properties were analyzed by profilometry, UV-Vis spectrophotometry, x-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Additionally, three ZnO thin films were used to analyze the photocatalytic performance by using an $\pmb{1x10}^{-\pmb{5}}$ molar aqueous methylene blue (MB) solution, under the irradiation of ultraviolet light with a wavelength of 232 nm, during 5 h. The degradation of MB was carried out by absorbance measurements in the range of 400 to 800 nm every 30 min. The ZnO films showed a wurtzite hexagonal structure with a preferential growth in the (002) planes and good homogeneity. The results obtained from the study of the degradation of methylene blue showed that the ZnO film with a thickness of 400 nm presented the best photocatalytic response.
Databáze: OpenAIRE