Photocatalytic Active Nanorutile TiO2: Synthesis Characterization and Photocatalysis Tests

Abstract

We are able to produce nanoscale rutile TiO2 product from titanium mineral via a modified hydrothermal synthesis method, with the inclusion of an alkaline fusion stage. The mineral was totally dissolved in an acidic solution, and is followed by the nucleation reaction, producing anatase having a crystallite size of 15.4nm. Annealing of the nanoanatase resulted in a phase transformation process, and the rutile phase was detected when annealed at 800°C. Single rutile phase was achieved when the anatase sample was annealed at 1,000°C. As the starting mineral contains a significant amount of Nb and Zr impurities, these elements are naturally doped into the nanosized rutile. A paint formulation was then produced by adding 2g of this nanoanatase/nanorutile into the paint. Using this nanotitania added paint under visible light source, a photocatalytic study on the degradation of methylene blue was conducted. A comparative study was also carried out with commercial grade pure nanorutile under similar condition. The result showed that our nanorutile managed to degrade the methylene blue to almost a similar 85% degradation compared to the commercial pure nanoanatase. A pure nanorutile product resulted in a much lower photodegradation rate, standing at 77%. Tests on the photodegradation of nitrous oxide gas also reveals that the nanorutile paint was able to degrade the VOC in much shorter times compared to the other nanotitania added paints.