Crystallization and Optical Behaviour of Nanocomposite Sol-Gel TiO₂:Ag Films

Area of Science:

• Materials Science
• Nanotechnology
• Thin Film Deposition

Background:

• Titanium dioxide (TiO2) is a versatile material with applications in catalysis, sensors, and photovoltaics.
• Doping TiO2 with noble metals like silver (Ag) can modify its properties for enhanced performance.
• Understanding the impact of doping and annealing on TiO2 film characteristics is crucial for material optimization.

Purpose of the Study:

• To investigate the structural, morphological, vibrational, and optical properties of sol-gel spin-coated TiO2 films doped with silver.
• To determine the influence of varying annealing temperatures (300-600 °C) on the Ag-doped TiO2 films.
• To explore the plasmonic effects and optical band gap modifications induced by silver nanoparticles (Ag NPs) in the TiO2 matrix.

Main Methods:

• Sol-gel spin coating for depositing TiO2 and Ag-doped TiO2 films.
• Field Emission Scanning Electron Microscopy (FESEM) for morphological analysis.
• X-ray Diffraction (XRD) for structural characterization.
• Fourier Transform Infrared (FTIR) spectroscopy for vibrational analysis.
• UV-VIS spectroscopy for optical property assessment.

Main Results:

• Ag doping resulted in rougher TiO2 film surfaces with the formation of Ag nanoparticles and AgO phases.
• XRD confirmed the presence of anatase and rutile TiO2 phases, dependent on Ag concentration and processing conditions.
• FTIR showed that silver incorporation altered the vibrational properties of TiO2 films.
• UV-VIS spectroscopy indicated increased absorbance in the visible range due to Local Surface Plasmon Resonance (LSPR) of Ag NPs.
• Ag doping led to a reduction in the optical band gap of the TiO2 films.

Conclusions:

• Sol-gel spin coating is effective for producing Ag-doped TiO2 films with tunable properties.
• Annealing temperature significantly influences the phase composition and structural integrity of TiO2:Ag films.
• Ag doping introduces plasmonic behavior and narrows the band gap, enhancing optical absorption for potential applications.