Abstract
Abstract Transparent barium titanoborate glass-ceramics bearing TiO<inf>2</inf> (anantase) nanocrystals were prepared by the conventional melt-quenching and subsequent heat treatment of 35BaO-xTiO<inf>2</inf>-110B<inf>2</inf>O<inf>3</inf> (in mol) (x = 20, 25, and 30) glasses. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) results clearly reveal the formation of highly-crystalline anatase nanocrystals in glass matrices. The average crystal size ranges from ∼10 to 20 nm according to TiO<inf>2</inf> contents. Non-isothermal kinetic analyses were performed to understand the crystallization behavior of each glass using differential scanning calorimetry (DSC) scan curves. With the increase of TiO<inf>2</inf> contents in the glass, the crystallization peak temperature of TiO<inf>2</inf> decreases, while the activation energy for crystallization increases. We propose a possible mechanism for the formation of TiO<inf>2</inf> nanocrystals based upon kinetic analysis results and structural changes in barium titanoborate glass matrices according to TiO<inf>2</inf> contents. The nanocrystalline glass-ceramics show ∼60-75% visible light transmittance and sharp UV-light absorption edges at ∼387 nm, corresponding to the energy band gap of anatase (3.2 eV). They show apparent photocatalytic properties and ∼70% of methylene blue solution was decomposed within 180 min.
Original language | English |
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Article number | 34621 |
Pages (from-to) | 1022-1027 |
Number of pages | 6 |
Journal | Journal of Alloys and Compounds |
Volume | 647 |
DOIs | |
Publication status | Published - 2015 Jul 8 |
Keywords
- Anatase
- Glass-ceramic
- Nanocrystals
- Non-isothermal kinetics
- Photocatalytic effect
ASJC Scopus subject areas
- Mechanical Engineering
- Mechanics of Materials
- Materials Chemistry
- Metals and Alloys