Comparative study of the TiO2 nanopowders prepared from different precursors and chemical methods for heterogeneous photocatalysis application

• Published in: Journal of thermal analysis and calorimetry 2022-12, Vol.147 (23), p.13111-13124
• Main Authors: Pandele-Cusu, Jeanina, Petrescu, Simona, Preda, Silviu, Petcu, Gabriela, Ciobanu, Madalina, Predoana, Luminita
• Format: Article
• Language: English
• Subjects: Ammonia; Analytical Chemistry; Anatase; Catalytic activity; Chemistry; Chemistry and Materials Science; Comparative studies; Crystallization; Degradation; Differential thermal analysis; Dyes; Inorganic Chemistry; Measurement Science and Instrumentation; Photocatalysis; Physical Chemistry; Polymer Sciences; Precursors; Scanning electron microscopy; Sol-gel processes; Thermodynamic properties; Titanium; Titanium dioxide
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-022-11544-9

A comparative thermal analysis study was realized by the thermogravimetric and thermodifferential analysis (TG/DTG/DTA) and differential scanning calorimetry (DSC) on TiO 2 system. This study is to establish the influence of the preparation method on thermal behavior of powders obtained by different methods as follows: the sol–gel (SG), microwave-assisted sol–gel (MW) and hydrothermal (HT) methods. Titanium (IV) ethoxide, titanium (IV) isopropoxide and titanium (IV) butoxide were used as TiO 2 precursors, as well as the parental alcohol as solvent, and the hydrolyzing agent (ammonia containing water) was added drop by drop to obtain a solution with pH 10. Based on TG/DTG/DTA results, the temperature of 450 °C was chosen for the processing of powders in air. Morphology and structure of the calcinated powders were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The SEM images show spherical nano-sized particles and X-ray diffractograms for all samples calcinated at 450 °C show crystallization in a single phase of TiO 2 (anatase). According to the activation energy, E a , values calculated by Kissinger and Ozawa methods, amorphous-to-anatase transition is facilitated in the microwaved-assisted samples in comparison with the sol–gel derived samples. The photocatalytic activity of the TiO 2 samples toward the degradation of methyl orange (MO) was evaluated, the sample denoted Ti-Bu-SG being the most effective removing a total of ~99% of the dye in 180 min, while Ti-Bu-MW presented the lowest degradation efficiency, about 82%.