Monitoring the Structure Evolution of Titanium Oxide Photocatalysts: From the Molecular Form via the Amorphous State to the Crystalline Phase
| Autor: | Ezgi Onur Şahin, Siyuan Zhang, Harun Tüysüz, Candace K. Chan, Claudia Weidenthaler, Joohyun Lim, Christina Scheu, Wolfgang Schmidt, Yitao Dai |
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| Rok vydání: | 2021 |
| Předmět: |
Anatase
crystallization Hot Paper chemistry.chemical_element Catalysis law.invention law PDF (pair distribution function) Crystallization Full Paper Chemistry Electron energy loss spectroscopy Organic Chemistry General Chemistry Full Papers Nanocrystalline material Amorphous solid Titanium oxide Chemical engineering ddc:540 Photocatalysis reduced titania nanoparticles photocatalysis Titanium |
| Zdroj: | Chemistry (Weinheim an Der Bergstrasse, Germany) Chemistry – A European Journal Chemistry-a European journal 27(45), 11600-11608 (2021). doi:10.1002/chem.202101117 |
| ISSN: | 1521-3765 0947-6539 |
| DOI: | 10.1002/chem.202101117 |
| Popis: | Chemistry - a European journal 27(45), 11600 - 11608 (2021). doi:10.1002/chem.202101117 Amorphous Ti$_x$O$_y$ with high surface area has attracted significant interest as photocatalyst with higher activity in ultraviolet (UV) light-induced water splitting applications compared to commercial nanocrystalline TiO$_2$. Under photocatalytic operation conditions, the structure of the molecular titanium alkoxide precursor rearranges upon hydrolysis and leads to higher connectivity of the structure-building units. Structurally ordered domains with sizes smaller than 7 Å form larger aggregates. The experimental scattering data can be explained best with a structure model consisting of an anatase-like core and a distorted shell. Upon exposure to UV light, the white Ti$_x$O$_y$ suspension turns dark corresponding to the reduction of Ti$^{4+}$ to Ti$^{3+}$ as confirmed by electron energy loss spectroscopy (EELS). Heat-induced crystallisation was followed by in situ temperature-dependent total scattering experiments. First, ordering in the Ti−O environment takes place upon to 350 °C. Above this temperature, the distorted anatase core starts to grow but the structure obtained at 400 °C is still not fully ordered. Published by Wiley-VCH, Weinheim |
| Databáze: | OpenAIRE |
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