Structural phase transitions in brookite-type TiO2 under high pressure

Brookite, the Least Known TiO2 Photocatalyst

“…Inorganic and organic precursors such as TiCl 4 [21,24,[49][50][51][52][53][54][55][56][57][58], Ti(SO 4 ) 2 [18,[59][60][61][62], TiOSO 4 [63,64], TiCl 3 [3,19,[65][66][67][68], TiOCl 2 [16,69,70], titanate nanotubes [69,[71][72][73], titanium tetraisopropoxide [25,[74][75][76], titanium butoxide [77][78][79][80][81] and titanium tetraethoxide [82] have been employed.…”

“…Xie et al [18] observed that the crystallinity of brookite increased with increasing the hydrolysis time. Ultrafine brookite powders were prepared by Luo et al [62] by hydrolyzing Ti(SO 4 were obtained by thermal decomposition of the oxalate hydrate at a temperature between 300 and 400 °C for 4 h under an air atmosphere [64]. As shown in Figure 7, the eggshell morphology of the Ti 2 O 3 (H 2 O) 2 (C 2 O 4 )·3H 2 O compound was retained despite the creation of porosities arising from the removal of water and oxalate species.…”

TiO2 nanocomposite based polymeric membranes: A review on performance improvement for various applications in chemical engineering processes

“…Besides, the author believed that the observed changes in membrane morphology from spherulitic to fibrous structure might be due to the structural changes from α to β which happened after loading of TiO 2 (Fig.9). Furthermore, structural phase transition of TiO 2 nanoparticles has been studied using energy-dispersive X-ray diffraction and measuring the change of enthalpy by other researchers [158,159].…”

From superhard to hard: A review of transition metal dioxides TiO2, ZrO2, and HfO2 hardness

“…We also note that the coordination number increases for high-pressure phases, as expected. Additionally, for the case of TiO 2 , there are three phases found at ambient conditions: brookite (rare polymorph [26]) and anatase are stable phases, whereas rutile (RT) is a metastable phase formed at high temperatures. Additionally, there are other observed phases at high temperature for ZrO 2 and HfO 2 : tetragonal [84,85] and cubic [86,87] phases.…”