EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Water pollution by organic chemicals is a rapidly growing problem. Classical water treatment methods are associated with certain risks in the decomposition of organic dyes. Therefore, the need for new solutions emerges which combine innovations and classical methods, to reduce the risks. The possible solution could be semiconductor photocatalysis, which can also be applied in other areas, such as photocatalytic water decomposition, CO2 reduction. Formation of TiO2 based heterostructures, i.e. decoration TiO2 with metallic nanostructures can extend the life of electron-hole pairs and accelerate reduction reactions, or allow the use of visible light via localized surface plasmon resonance. The size and distribution of metal nanostructures influence mentioned processes. Thus, it is important to be able to form metal nanostructures of desired characteristics. In this work, a two-step process was conducted. First TiO2 thin films of 200 nm thickness were deposited on room temperature (20 ºC) SiO2 substrates from two Ti targets using the reactive magnetron sputtering technique. Subsequently, thin metal films (5 nm and 10 nm) were formed on the surface of TiO2 thin films. After deposition, metal/TiO2 structures were annealed at 300 ºC, 350 ºC, 400 ºC, 450 ºC temperatures for 60 min. The distribution of metal nanostructures was investigated by scanning electron microscope. The chemical properties were determined using energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy methods. Finally, the X-ray diffraction method was used to investigate the crystalline structure of metal/TiO2 heterostructures. Different distribution of crystalline nanostructures was observed depending on annealing temperature, and thickness of the thin metal films. The higher density of metal nanoclusters was obtained when thinner metal films were annealed.