Abstract
Titanium dioxide coatings have potential applications including photocatalysts for solar assisted hydrogen production, solar water disinfection and self-cleaning windows. Herein, we report the use of suspension plasma spraying (SPS) for the deposition of conformal titanium dioxide coatings. The process utilises a nanoparticle slurry of TiO2 (ca. 6 and 12 nm respectively) in water, which is fed into a high temperature plasma jet (ca. 7000-20 000 K). This facilitated the deposition of adherent coatings of nanostructured titanium dioxide with predominantly anatase crystal structure. In this study, suspensions of nano-titanium dioxide, made via continuous hydrothermal flow synthesis (CHFS), were used directly as a feedstock for the SPS process. Coatings were produced by varying the feedstock crystallite size, spray distance and plasma conditions. The coatings produced exhibited ca. 90-100% anatase phase content with the remainder being rutile (demonstrated by XRD). Phase distribution was homogenous throughout the coatings as determined by micro-Raman spectroscopy. The coatings had a granular surface, with a high specific surface area and consisted of densely packed agglomerates interspersed with some melted material. All of the coatings were shown to be photoactive by means of a sacrificial hydrogen evolution test under UV radiation and compared favourably with reported values for CVD coatings and compressed discs of P25.
Original language | English |
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Pages (from-to) | 12680-12689, Impact Factor: 7.4 |
Number of pages | 20 |
Journal | Journal of Materials Chemistry A |
Volume | 3 |
Issue number | 24 |
Early online date | 21 May 2015 |
DOIs | |
Publication status | Published - 2015 |
Keywords
- SENSITIZED SOLAR-CELLS
- HVSFS TIO2 COATINGS
- WATER-PURIFICATION
- THIN-FILMS
- ANATASE
- DIOXIDE
- POWDERS
- RUTILE
- MICROSTRUCTURE
- PHOTOACTIVITY