School of Engineering and Materials Science
Research Student Awards
PhD Thesis: High throughput discovery of TiO2 catalysts and pigments
Author: SAEED, Faraz A
Supervisor(s): Julian Evens
The study in this thesis concentrates on developing a new method for synthesising and characterising combinatorial libraries of co-doped TiO2 catalysts and pigments. Doping ink-jet printed TiO2 samples with metal nitrate solutions provides a quick and versatile route for synthesising combinatorial libraries. A method has been developed for multifunctional high throughput characterisation of these libraries.
The London University Search Instrument (LUSI) ink-jet printer was used for printing various titanium dioxide inks. The small solid free-formed titania discs were co-doped with iron and gadolinium using nitrate precursors. In another approach, titanium dioxide well plates were also developed as substrate for doping by metal nitrates.
A novel characterisation technique capable of scanning combinatorial libraries for colour, photoluminescence and photocatalysis has been developed in this project. This is a multifunctional characterisation tool that is based on a luminescence spectrophotometer and an optical fibre probe. The spectrophotometer has been modified such that it can scan solid samples down to 2 mm diameter. This single instrument can determine the reflectance, colour, fluorescence, fluorescent colour, and photocatalytic activity of the samples. The design is flexible and allows scanning solid thick films, thin films in transmission mode as well as liquid samples. The scanning times are very short; for instance, a library of twenty five members can be scanned for both colour and photoluminescence in less than an hour. A method for colour measurements of non-luminescent samples is introduced that is exceptionally more efficient than the conventional colour measurement using two monochromator instruments. In this new set-up the colour of non-luminescent samples can be measured as efficiently as standard colour measuring instruments with additional advantage of colour measurement of a fluorescent sample. A small scale photocatalytic reactor was also built for carrying out 25 reactions simultaneously.