Suspension plasma sprayed coatings using dilute hydrothermally produced titania feedstocks for photocatalytic applications

B. W. Robinson*, C. J. Tighe, R. I. Gruar, Andrew Mills, I. P. Parkin, A. K. Tabecki, H. L. de Villiers Lovelock, J. A. Darr

*Corresponding author for this work

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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 languageEnglish
Pages (from-to)12680-12689, Impact Factor: 7.4
Number of pages20
JournalJournal of Materials Chemistry A
Volume3
Issue number24
Early online date21 May 2015
DOIs
Publication statusPublished - 2015

Keywords

  • SENSITIZED SOLAR-CELLS
  • HVSFS TIO2 COATINGS
  • WATER-PURIFICATION
  • THIN-FILMS
  • ANATASE
  • DIOXIDE
  • POWDERS
  • RUTILE
  • MICROSTRUCTURE
  • PHOTOACTIVITY

Cite this

Robinson, B. W., Tighe, C. J., Gruar, R. I., Mills, A., Parkin, I. P., Tabecki, A. K., Lovelock, H. L. D. V., & Darr, J. A. (2015). Suspension plasma sprayed coatings using dilute hydrothermally produced titania feedstocks for photocatalytic applications. Journal of Materials Chemistry A, 3(24), 12680-12689, Impact Factor: 7.4. https://doi.org/10.1039/c4ta05397d