Enhancement in Photocatalytic Activity of SrTiO₃ by Tailoring Particle Size and Defects

Abstract

The photocatalytic activity of polycrystalline strontium titanate (SrTiO 3 ) powder having different particle sizes is investigated. The powders of SrTiO 3 are ball‐milled for different time durations and characterized by x‐ray diffractometer (XRD), high‐resolution transmission electron microscopy (HRTEM), x‐ray absorption spectroscopy (XAS), UV–visible, photoluminescence (PL), and Raman spectroscopy. The crystallite size, particle size, and crystallinity of SrTiO 3 decrease with an increase in ball milling time duration. While the HRTEM images show a significant reduction in the particle sizes and lattice dislocation after ball milling, the PL spectra indicate a significant enhancement of defects and vacancies in the ball‐milled SrTiO 3 . The XAS measurements confirm the reduction in the valency of Ti ions due to oxygen vacancies. The photocatalytic activity of SrTiO 3 is investigated using methylene blue dye under the UV‐Visible light illumination. A rapid degradation is observed for the highest time ball‐milled SrTiO 3 . Small particles provide shorter path and thus decrease the probability of recombination of the photogenerated electron–hole pairs when compared with large ones.