Synthesis and Characterization of CdTiO_3@S Composite: Investigation of Photocatalytic Activity for the Degradation of Crystal Violet Under Sun Light

摘要

CdTiO3 was synthesized by hydrothermal method at low temperature of 180 degrees C for 24 h. CdTiO3@S composite with plate-like morphology was synthesized by mixing CdTiO3 and S powder under post-annealing at 600 degrees C for 2 h. The as-synthesized samples were investigated by techniques XRD, FE-SEM, EDS, TEM, FT-IR, TG-DSC, BET. The results showed that the synthesized of CdTiO3@S composite has led to the creation of defects and skew deviations in crystalline lattice. Optical properties and photocatalytic activity were studied using DRS and UV-Vis spectrophotometer. UV-Vis DRS indicated absorption peaks extended towards visible region. Band gap energy values were determined by Tauc plot for direct transitions which the values of 3.28 eV and 2.75 eV were obtained for CdTiO3 and CdTiO3@S respectively. Photocatalyst performance of CdTiO3 and CdTiO3@S were carried out for the degradation of crystal violet (CV) under natural sunlight. The results showed that the degradation efficiency of CdTiO3@S composite (99%) was better than that of pure CdTiO3 (35%), which is due to the presence of narrow band gap energy of CdTiO3@S. The effect of examining different photocatalytic parameters indicated that, photocatalytic activity of CdTiO3@S composite increases with decreasing CV dye concentration, increasing the photocatalyst dosage and in acidic pH. Kinetics studies have shown that the degradation of CV by the as-synthesized of photocatalysts follows the pseudo-first-order kinetics and the rate constant achieved for CdTiO3@S (k = 76.10(-4) min(-1)) was much greater than of CdTiO3 (k = 4.10(-4) min(-1)).