Investigation of the thermal decomposition of a new titanium dioxide material

0463506 - ÚACH 2017 RIV NL eng J - Journal Article
Palkovská, Monika - Slovák, V. - Šubrt, Jan - Boháček, Jaroslav - Barbieriková, Z. - Brezová, V. - Fajgar, Radek
Investigation of the thermal decomposition of a new titanium dioxide material.
Journal of Thermal Analysis and Calorimetry. Roč. 125, č. 3 (2016), s. 1071-1078. ISSN 1388-6150. E-ISSN 1588-2926
R&D Projects: GA ČR(CZ) GA14-20744S; GA MŠMT(CZ) 7AMB14SK178
Institutional support: RVO:61388980 ; RVO:67985858
Keywords : Titanium dioxide * Rod-shaped structure * Thermal analysis * Evolved gas analysis * EPR spectroscopy
Subject RIV: CA - Inorganic Chemistry; CF - Physical ; Theoretical Chemistry (UCHP-M)
Impact factor: 1.953, year: 2016

A new type of TiO2 material has been prepared from titanium(IV) oxysulfate via precipitation by cold ammonia solution and drying at room temperature. The structure remains unchanged during the preparation (controlled hydrolysis), and titania material with a similar rod-shaped structure is created. The decomposition process has been evaluated by TA/MS analysis as a three-step process. The first step was characterized by water and carbon dioxide loss, the second step is represented by the evolution of residual water and ammonia, and the third step is represented by a very sharp exothermic peak due to the phase transition (crystallization of amorphous phase to anatase) together with a small mass loss caused by evolution of oxygen and nitrous oxide. EPR spectra obtained in the temperature range 100-250 K confirmed the presence of Ti(III) ions and oxygen vacancies for the TiO2 precursor annealed up to 550 degrees C in a vacuum. Annealing to 500 degrees C resulted in the generation of paramagnetic Ti(III) centers and nitrogen species (N-b and NO) in anatase lattice.
Permanent Link: http://hdl.handle.net/11104/0262686