Microwave-Assisted Hydrothermal Synthesis of Brookite Nanoparticles from a Water-Soluble Titanium Complex and Their Photocatalytic Activity

Abstract

Nanoparticles of brookite titanium oxide were prepared by microwave-assisted hydrothermal MH method at 200? C heating time 5 min for 0-60 minutes starting from the titanium peroxo glycolate complex in basic solution. The effect of microwave heating on the morphology of the brookite particles was examined. The samples were characterized by X-ray diffraction XRD , Raman spectroscopy and transmission electron microscopy TEM. It was found that all powders were composed of single phase brookite and contained two different types of particles. The activity in photodecomposition of oxalic acid by the samples prepared using MH method was higher than activities of brookite nanoparticles synthesized by the conventional hydrothermal method.

Brookite, the Least Known TiO2 Photocatalyst

“…Recently, pure brookite has been successfully synthesized by hydrothermal treatment of water-soluble titanium complexes [84] such as titanium-peroxo-glycolate [16,[85][86][87][88] and titanium bis(ammonium lactate) dihydroxide [23,89].…”

“…A microwave-assisted hydrothermal treatment of the titanium-peroxo-glycolate complex at 200 °C for 0-60 min allowed to synthesize brookite particles with a size smaller than that obtained by the conventional hydrothermal method [87]. Lately, nanocrystalline single phase brookite was also prepared by decomposition at 200 °C for 4 h of a water-soluble titanium complex with ethylenediaminetetraacetic acid (EDTA) [91].…”

“…With increasing temperature, the crystallinity increased and the photoactivity was higher. An enhancement of activity was achieved by employing brookite particles with a smaller size obtained by microwave heating of the titanate-glycolate complex [87]. Further studies evidenced that brookite synthesized from a water soluble Ti-EDTA complex had a considerably higher activity for the decomposition of NO than that of brookite prepared from the titanate-glycolate complex [91].…”

Microwave Hydrothermal and Solvothermal Processing of Materials and Compounds

“…Similar applied methods led to a variety of its distinct crystalline phases obtained in different reports. Thus, nanoparticles of brookite-type TiO2 were prepared at 200 o C (H-MW-heating time 5 min) for 0-60 min starting from the titanium peroxo glycolate complex in basic solution (Morishima et al, 2007). The activity in photodecomposition of oxalic acid by the samples prepared using H-MW technique was higher than activities of brookite nanoparticles prepared by the conventional hydrothermal method.…”

Hydrothermal Reaction by Microwave Heating for Synthesis of LiFePO₄ as Cathode Material

“…Therefore, we have paid our attention to the microwave hydrothermal (MH) heating reaction. It is known to have rapid heating rate, advance of convection, high crystallization rate, and often kinetics of chemical reactions is also different [15] due to an essentially non-equilibrium process [16].…”