Influence of high energy ball milling on structural, microstructural and optical properties of TiO2 nanoparticles

The influence of high-energy ball milling on structural, microstructural, and optical properties of TiO2 by modifying the nanoparticle size was studied. Five samples were extracted at different milling times (0, 2, 4, 8, and 13 h). The average particle sizes estimated by dynamic light scattering (DLS) were 205, 155.8, 116.8, 82.9, and 82.7 nm at 0, 2, 4, 8, and 13 h, respectively. X-ray diffraction analysis confirmed progressive broadening of the peaks as the milling time elapsed. Besides, a correlation was found between d spacing and the average crystal size. The UV-Vis diffuse reflectance spectra of TiO2 revealed a decrease in reflectance due to particle size reduction. Similarly, an alteration of the bandgap transition energy was presented, whose values gradually decreased from 2.966 eV to 2.861 eV for the sample without and with the maximum duration milling performed (13 h), respectively. Likewise, the SEM analysis showed a distribution in nanoparticle size that became more homogeneous and smaller average grain size as the milling duration was longer.

Automated summary

High-energy ball milling was used to modify the nanoparticle size of TiO2 and study its effects on structural, microstructural, and optical properties. Increasing milling time resulted in smaller particle sizes, broadening of X-ray diffraction peaks, decreased reflectance in UV-Vis spectra, and a decrease in bandgap transition energy. SEM analysis also showed a more homogeneous distribution of nanoparticle size with longer milling duration.