Preparation and Characterization of Teo2 Nan particles by Pulsed Laser Ablation in Water

Abstract

Tellurium dioxide (TeO 2 ) nanoparticles were synthesized directly by pulsed laser ablation using Nd:YAG, λ=1064nm laser in pure water. The AFM and XRD measurements, in combination with FTIR and UV-Vis spectroscopy have been employed for the characterization of the prepared samples. The effects of operating parameters on nanoparticles composition, production rate and size were also studied. The XRD measurements revealed crystallization structure of TeO 2 nanoparticles. The particle diameter by use of Scherer's equation was calculated to be about 28. nm and confirmed by AFM measurements. The UV-vis spectrum of the colloidal nanoparticles shows maximum absorbance around the UV region, indicating the formation of TeO 2 nanoparticles, which confirmed by FTIR.

Synthesis of Ultrawide Band Gap TeO2 Nanoparticles by Pulsed Laser Ablation in Liquids: Top Ablation versus Bottom Ablation

“…By using the Tauc plot methodology, their energy band gap was determined to be around ∼5.8 eV (Figure d). Both values of energy band gap are in agreement with the values reported in the literature, Khalef and Hesabizadeh et al Theoretically, it is well known that by shrinking the size of a semiconductor, its energy band gap increases . At the nanoscale, size effects may have two origins: surface effects and quantum effects .…”

“…Colloids produced by both PLAL protocols are shown in Figure . Both colloids exhibited a dark gray color, characteristic of TeO 2 nanoparticles being produced, as already observed by Khalef and Hesabizadeh et al By shining a red laser pointer through the colloid, the red laser light (λ = 650 nm) is being scattered, indicating the presence of particles within the sample. This phenomenon is known as the Tyndall effect…”

“…So far, they have been produced by different methods such as spray analysis, sonochemistry, hydrothermal, , evaporation, biosynthesis, wet chemistry, and pulsed laser ablation in liquids (PLAL, Table ). − PLAL offers several advantages in comparison to other synthesis techniques. First, PLAL does not require capping ligands as wet chemistry does. − Specifically, PLAL produces nanoparticles with clean surfaces because it relies on electrostatic repulsion instead of stearic repulsion.…”