Fabrication and Characterisation of ZnoTio2 Core/Shell Nanowires Using a Versatile Kinetics-Controlled Coating Growth Method

• Main Author: Alshehri, Naif Ahmed
• Format: Publication
• Language: English
• Published: SSRN 2022

Zinc oxide nanowires (ZnO NWs) were fabricated with a titanium oxide (TiO2) shell using a simple wet chemical method, aiming to provide a strategy for the fabrication of a scalable and reproducible ZnO@TiO2 heterostructure with precisely engineered TiO2 layer thickness. The reaction parameters, temperature, time and ammonia concentration, were changed in order to investigate their impact upon the heterostructures. A novel photonic annealing process was applied to both ZnO NWs and ZnO@TiO2 heterostructures, in order to improve their optical properties. Transmission and scanning electron microscopy as well as X-ray mapping confirm the core shell structure and indicate that the TiO2 shell can be produced at room temperature, and that the reaction time does not impact on the TiO2 shell thickness with one hour sufficient to produce the TiO2 shell. Temperature also had no measurable impact. However, the ammonia concentration had a significant influence on the TiO2 shell thickness, which could be precisely controlled from ∼2.5 nm up to ∼90 nm by changing the ammonia content from 300 µl to 400 µl. The 2.5 nm shell showed an anatase crystalline structure whilst the thicker shell were amorphous. X-ray photoelectron spectroscopy confirmed the oxidation state of Ti is consistent with TiO2