Desenvolvimento de nanocristais de dióxido de titânio puros e dopados com níquel e sua aplicação na detecção de ácido ascórbico

Abstract

Titanium dioxide (TiO2) nanocrystals have several physical, chemical and biological properties such as ultraviolet absorption and emission, photocatalysis and osseointegration properties. The incorporation of transition metals in nanocrystals generates new properties that are tuned according to the concentration and type of dopant. However, works investigate the effect of structural, optical and electrical properties with the incorporation of nickel ions in the crystalline structure of TiO2, being the main motivation of this work. The structural, optical and electrical properties of pure TiO2 nanocrystals containing different concentrations of nickel were investigated by X-ray diffraction (XRD), optical absorption spectroscopy (AO) and cyclic voltammetry (VC), respectively. Based on XRD results, it was confirmed the formation of pure and nickel-doped TiO2 nanocrystals in the anatase phase and that the nickel concentration did not alter the crystalline phase. In the AO results it was verified the absorption in the ultraviolet of the pure TiO2 nanocrystals and that with the doping the absorption in the visible was verified and that it intensifies with the concentration. In the VC results, it was verified through the data obtained that the nanocrystals, pure and doped, were attached to the electrochemical sensors, and that the electrical properties showed differences with the concentration of nickel doping. Therefore, in this work it was possible to confirm the formation of pure and nickel-doped TiO2 nanocrystals in the anatase phase and that the nickel concentration only altered the optical and electrical properties.