Thermal reactions in mixtures of micron-sized silicon monoxide and titanium monoxide: redox paths overcoming passivation shells

0484216 - ÚACH 2019 RIV NL eng J - Journal Article
Jandová, V. - Pokorná, D. - Kupčík, Jaroslav - Bezdička, Petr - Křenek, T. - Netrvalová, M. - Cuřínová, P. - Pola, J.
Thermal reactions in mixtures of micron-sized silicon monoxide and titanium monoxide: redox paths overcoming passivation shells.
Research on Chemical Intermediates. Roč. 44, č. 1 (2018), s. 503-516. ISSN 0922-6168. E-ISSN 1568-5675
Institutional support: RVO:61388980
Keywords : Silicon monoxide * Titanium monoxide * High-temperature * Oxygen-transfer reactions * Titanium suboxides * Titanium silicide * Methylene blue depletion
OECD category: Inorganic and nuclear chemistry
Impact factor: 2.064, year: 2018

Silica–titania mixed oxides and composites have been extensively studied, whereas the titanium monoxide (TiO)–silicon monoxide (SiO) counterparts still remain to be explored. Here, we report on structural changes in heated SiO–TiO mixtures. The changes in composition in intimately mixed μm-sized particles of TiO and SiO heated at 1000 °C were examined by FTIR, UV–Vis and Raman spectroscopy, X-ray diffraction and electron (SEM and TEM) microscopy. They are shown to involve depletion of crystalline TiO and formation of titanium suboxides (Ti2.5O3, Ti2O3), rutile, elemental silicon, titanium silicide Ti5Si3 and amorphous binary SiOx, TiOx and ternary SixTiyOz nano-structures. These constituents of the developed Si/Ti/O composite are explained by SiO disproportionation, reduction of TiO by silicon, oxygen transfer (redox) reactions between TiOx and SiOx species and the combination of Ti and Si to obtain titanium silicide. The produced Si/Ti/O composite absorbs visible light and its solar-light photocatalytic activity in decolorization of methylene bBlue is compared to that of the unheated SiO, TiO and Ti5Si3 powders.
Permanent Link: http://hdl.handle.net/11104/0282019