Estrutura e propriedades fotoluminescentes do TiO₂ funcionalizado com nanopartículas metálicas

Abstract

The advancement of nanotechnology has driven the development of new materials with enhanced properties for technological applications. Among these materials, titanium dioxide (TiO₂) stands out, widely studied for its optical, electrical, and photoelectronic properties, as well as its potential for applications in photocatalysis, sensors, solar cells, among others1. However, limitations such as low response in the visible region of the spectrum and rapid recombination of electron-hole pairs reduce its efficiency2. To overcome these restrictions, this work proposes the surface modification of TiO₂ with metallic nanoparticles of silver (Ag) and copper (Cu), aiming to investigate the effects of these modifications on the photoluminescent properties of the material. TiO₂ was synthesized by the modified sol-gel method and thermally treated via hydrothermal means. Subsequently, samples were functionalized with different concentrations (0.5%, 2.0%, and 5.0%) of Ag and Cu by photoreduction under UV radiation. The samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and fluorescence spectroscopy. XRD analysis confirmed the presence of anatase and brookite phases, with anatase predominating. FTIR spectra revealed characteristic bands of Ti-O and Ti-O-Ti bonds, as well as OH group stretching. The observed structural and optical modifications suggest that the presence of metallic nanoparticles significantly influences the material's properties, potentially directing its application to areas such as sensors and photonic devices.