Abstract

Background: Titania (TiO₂) is an environment-friendly semiconductor system with immense potential in the fields of photocatalysis, photovoltaics, sunscreen lotion and so on. In the past, nanoscale titania with inclusion of suitable dopants, were shown to improve optoelectronic, photochromic as well as antibacterial responses at large.

Objective: To obtain a qualitative assessment of introduction of mixed phase, modified radiative emission and thermal stability due to inclusion of Ag into titania system.

Method: A simple sol-gel route has been employed to synthesize un-doped and Ag-doped nano-titania systems.

Results: Apart from diffraction peaks due to anatase phase of titania, the respective peaks (121) and (110) due to brookite and rutile phases have been witnessed in case of Ag-doped systems. In the photoluminescence spectra, the near band edge emission (NBE) peak has been located at ~407 nm, whereas ∼ 430 nm peak is assigned to the self-trapped excitons (STE) localized on the TiO₆ ^2- octahedra. Thermogravimetric analysis (TGA) have revealed that, Ag- doped nano-titania systems could exhibit relatively low weight loss at high temperatures, as compared to their un-doped counterpart.

Conclusion: X-ray diffractograms have revealed the co-existence of adequate rutile and brookite phases, apart from the dominant anatase phase after inclusion of Ag into titania. The manifestation in near band edge emission and defect related emission intensities have been witnessed in the luminescence spectra. The Ag-doped samples are thermally more stable as compared to the un-doped nano-titania system.

Keywords: TiO₂ , nanoparticles, silver doping, photoluminescence, thermo-gravimetric, Ag-doped nano-titania.

Graphical Abstract