Synthesis and characterization of photocatalytic zinc oxide/titanium oxide (core/shell) nanocomposites

• Published in: Journal of alloys and compounds 2021-11, Vol.882, p.160777, Article 160777
• Main Authors: Mehr, Masoud Emami, Maleki-Ghaleh, Hossein, Yarahmadi, Mohadeseh, Kavanlouei, Majid, Siadati, M. Hossein
• Format: Article
• Language: English
• Subjects: Carrier density; Catalytic activity; Charge density; Core/Shell; Crystallites; Current carriers; Heterojunctions; Methylene blue; Morphology; Nanocomposites; Optical properties; Photocatalysis; Photocatalyst; Photoelectric effect; Photoelectric emission; Photoluminescence; Raman spectroscopy; Scanning electron microscopy; Sol-Gel; Sol-gel processes; Titanium dioxide; Titanium oxide; Titanium oxides; X-ray diffraction; Zinc oxide; Zinc oxides
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.160777

•Core/shell of ZnO/TiO2 was successfully achieved using the sol-gel method.•The core-shell heterojunction structured led to enhanced photocatalytic activity.•The Core/shell of ZnO/TiO2 prepared in the 15-min sol-gel time resulted in the optimal sample.•The optimal sample showed three times more photocatalytic activity in comparison to the ZnO.•The charge carrier density rose by 5 times in the optimal sample. [Display omitted] In this project, core/shell ZnO/TiO2 nanocomposite samples were prepared using the sol-gel method at different time spans. Characterization of the samples was done using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), as well as Raman spectroscopy. The optical properties were evaluated using UV–Vis diffuse reflectance and photoluminescence spectroscopies. The photocatalytic ability of all samples in the degradation of methylene blue (MB) dye by the radiation of Hydrargyrum medium-arc iodide (HMI) lamp was determined. The amount of charge carriers in the samples was calculated using the Mott-Schottky test. The XRD results showed that as the sol-gel preparation time increased, so did the TiO2 shell thickness and its crystallite size. The FE-SEM results revealed the spherical morphology of the samples. The sample prepared in the 15-min time span (ZnTi15) proved as the optimal sample, exhibiting 3 times more photocatalytic activity in comparison to the ZnO control sample. Also, the charge carrier density of the ZnTi15 sample was about 5 times more than that of the ZnO sample. Furthermore, the photoelectrochemical test showed a photocurrent density twice larger for the ZnTi15 sample, which could be attributed to the formation of the heterojunction at the ZnO/TiO2 interface.