Effect of amines on (peroxo)titanates : characterization and thermal decomposition
(2022) In Journal of Thermal Analysis and Calorimetry 147(8). p.5009-5022- Abstract
This report describes the thermal behaviour of nanotitania precursors and the influence of various amines and peroxide treatment on properties of TiO2. Thermal degradation of amine-containing amorphous (peroxo)titanates was examined via TG–DTA coupled with evolved gas analysis (EGA) by mass spectrometry in inert and oxidizing atmosphere. Crystallization to anatase and subsequent transformation to rutile are studied by in situ HT-XRD, which provided information about particle growth and mutual ratio between allotropic phases. In argon, the samples underwent a two-step degradation process, involving the release of moisture and decomposition or evaporation of amine, up to 450 °C, while in air conditions, the organic component... (More)
This report describes the thermal behaviour of nanotitania precursors and the influence of various amines and peroxide treatment on properties of TiO2. Thermal degradation of amine-containing amorphous (peroxo)titanates was examined via TG–DTA coupled with evolved gas analysis (EGA) by mass spectrometry in inert and oxidizing atmosphere. Crystallization to anatase and subsequent transformation to rutile are studied by in situ HT-XRD, which provided information about particle growth and mutual ratio between allotropic phases. In argon, the samples underwent a two-step degradation process, involving the release of moisture and decomposition or evaporation of amine, up to 450 °C, while in air conditions, the organic component could be oxidized in an additional third step at even higher temperatures. EGA confirmed the presence of the original amine in the amino-titanates, while the organic parts reacted with oxygen evolved from the peroxide group to form oxidation products (H2O, CO2 and NOx). The crystallization of nanoanatase began simultaneously/subsequently with the second degradation step. While peroxide treatment increased the initial particle size (from 5 to 40 nm), the choice of amine had a significant impact on the anatase formation temperature (325–425 °C). The anatase particle size increased with higher formation temperature after H2O2 treatment, while the particle size of amino-titanates decreased. The rutile formation temperature was directly dependent on the anatase particle size. Hitherto prepared amine-treated (peroxo)titanates demonstrated good thermal endurance of anatase nanoparticles (800–900 °C), which could be advantageous for various photocatalytic applications. The obtained results provide a method to synthetize tailored TiO2 with desired properties by adjusting the synthetic conditions (selection of precipitation agent and peroxide treatment) and annealing temperatures.
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- author
- Komárková, Bára ; Motlochová, Monika LU ; Slovák, Václav ; Ecorchard, Petra ; Bezdička, Petr ; Bavol, Dmytro and Šubrt, Jan
- organization
- publishing date
- 2022
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- (Peroxo)titanates, Amines, Evolved gas analysis, High temperature X-ray diffraction, Thermal degradation, TiO properties
- in
- Journal of Thermal Analysis and Calorimetry
- volume
- 147
- issue
- 8
- pages
- 5009 - 5022
- publisher
- Akademiai Kiado
- external identifiers
-
- scopus:85108268324
- ISSN
- 1388-6150
- DOI
- 10.1007/s10973-021-10925-w
- language
- English
- LU publication?
- yes
- id
- 0558e34f-f8aa-4d58-9e04-1dad7026b5e3
- date added to LUP
- 2021-07-12 14:32:39
- date last changed
- 2022-06-30 17:51:42
@article{0558e34f-f8aa-4d58-9e04-1dad7026b5e3,
abstract = {{<p>This report describes the thermal behaviour of nanotitania precursors and the influence of various amines and peroxide treatment on properties of TiO<sub>2</sub>. Thermal degradation of amine-containing amorphous (peroxo)titanates was examined via TG–DTA coupled with evolved gas analysis (EGA) by mass spectrometry in inert and oxidizing atmosphere. Crystallization to anatase and subsequent transformation to rutile are studied by in situ HT-XRD, which provided information about particle growth and mutual ratio between allotropic phases. In argon, the samples underwent a two-step degradation process, involving the release of moisture and decomposition or evaporation of amine, up to 450 °C, while in air conditions, the organic component could be oxidized in an additional third step at even higher temperatures. EGA confirmed the presence of the original amine in the amino-titanates, while the organic parts reacted with oxygen evolved from the peroxide group to form oxidation products (H<sub>2</sub>O, CO<sub>2</sub> and NO<sub>x</sub>). The crystallization of nanoanatase began simultaneously/subsequently with the second degradation step. While peroxide treatment increased the initial particle size (from 5 to 40 nm), the choice of amine had a significant impact on the anatase formation temperature (325–425 °C). The anatase particle size increased with higher formation temperature after H<sub>2</sub>O<sub>2</sub> treatment, while the particle size of amino-titanates decreased. The rutile formation temperature was directly dependent on the anatase particle size. Hitherto prepared amine-treated (peroxo)titanates demonstrated good thermal endurance of anatase nanoparticles (800–900 °C), which could be advantageous for various photocatalytic applications. The obtained results provide a method to synthetize tailored TiO<sub>2</sub> with desired properties by adjusting the synthetic conditions (selection of precipitation agent and peroxide treatment) and annealing temperatures.</p>}},
author = {{Komárková, Bára and Motlochová, Monika and Slovák, Václav and Ecorchard, Petra and Bezdička, Petr and Bavol, Dmytro and Šubrt, Jan}},
issn = {{1388-6150}},
keywords = {{(Peroxo)titanates; Amines; Evolved gas analysis; High temperature X-ray diffraction; Thermal degradation; TiO properties}},
language = {{eng}},
number = {{8}},
pages = {{5009--5022}},
publisher = {{Akademiai Kiado}},
series = {{Journal of Thermal Analysis and Calorimetry}},
title = {{Effect of amines on (peroxo)titanates : characterization and thermal decomposition}},
url = {{http://dx.doi.org/10.1007/s10973-021-10925-w}},
doi = {{10.1007/s10973-021-10925-w}},
volume = {{147}},
year = {{2022}},
}