Mo Doped TiO2 Thin Films

350 words maximum: (PLEASE TYPE) Ti02 thin films doped with 0.2 to 2.0 mol% Mo were spin coated on glass substrates and annealed in air at 450'C for 2 hours. The effects of varying the doping concentration on the mineralogical, microstructural, morphological, optical, and photocatalytic properties were determined using X-ray diffraction, scanning electron microscopy and atomic force microscopy, focused ion beam milling, UV-Vis spectrophotometry, and methylene blue and methyl orange tests, respectively. The distribution of Mo was determined by energy dispersive spectroscopy. All of the films consisted the polymorph anatase. Ths grain sizes were in the range 25·41 nm and the crystallite sizes were in the rage 2.3·4.2 nm. The thicknesses of all films were ~270 nm. Both grain size and crystallite size increased with doping level, where the former reached a maximum at the doping level of 1.0 mol% Mo and the latter maximised at 0.0% mol% Mo. The range of 0.8%. 1.0% mol% was identified as the solubility limit of Mo in anatase The absorption spectra indicated a red shift and the optical indirect band gaps of the films were calculated and found to decrease from 3.46 eV to 3.30 eV, with two tight bands of values, the lower corresponding to increasing Mo solubility and the higher corresponding to saturated solution. The methylene blue and methyl orange tests showed that doping did not have a beneficial effect on the photodecomposition. In fact, the degree of photoreduction was inversely proportional to the level of doping for both organic dyes. This was attributed to a combination of lattice distortion and a reduction in the surface actives sites associated with increasing crystallite size. Declaration relating to disposition of project thesis/dissertation I hereby gran~ to ! he Uni\•er;. it)' of New Sol! th Walo• cr its lgents the right to archiv~ •md to make available 1117 the~is or dissertation in whole or in part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all property rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstracts International (this is applicable to doctoral theses only). P.'~ . ~~ . 1 10.0 b· . :1 . "'"' . 1\A . Signature . 3.9. · ~~~~ ·~. J. . The University recognises that there may be exceptional circumstances requiring restrictions on copying or conditions on use. Requests for restriction for a period of up to 2 years must be made in writing. Requests for a longer period of restriction may be considered in exceptional circumstances andre uire the a roval of the Dean of Graduate Research. FOR OFFICE USE ONLY Date of completion of requirements for Award: THIS SHEET IS TO BE GLUED TO THE INSIDE FRONT COVER OF THE THESIS ORIGINALITY STATEMENT 'I hereby declare that this submission is my own work and to the best of my knowledge it contains no materials previously published or written by another person, or substantial proportions of material which have been accepted for \he • award of any other degree or diploma at UNSVV or any other educational institution, except where due acknowledgement is made in the thesis. Any contribution made to the research by others, with whom I have worked at UNSVV or elsewhere, is explicitly acknowledged in the thesis. I also declare that the intellectual content of this thesis is the product of my own work, except to the extent that assistance from others in the project's design and conception or in style, presentation and linguistic expression is acknowledged. ' Signed . HM. Otv. Date . '7? 0 . hY:! J . ~0.1} . COPYRIGHT STATEMENT 'I hereby grant the University of New South Wales or its agents the right to archive and to make available my thesis or dissertation in whole or part in the University libraries in all forms of media, now or here after known, subject to the provisions of the Copyright Act 1968. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation. I also authorise University Microfilms to use the 350 word abstract of my thesis in Dissertation Abstract International (this is applicable to doctoral theses only). I have either used no substantial portions of copyright material in my thesis or I have obtained permission to use copyright material; where permission has not been granted I have applied/will apply for a partial restriction of the digital copy of my thesis or dissertation. ' Signed . 11.6:~ . Qi~. Date . Jv. A~ . ~? ') . AUTHENTICITY STATEMENT 'I certify that the Library deposit digital copy is a direct equivalent of the final officially approved version of my thesis. No emendation of content has occurred and if there are any minor variations in formatting, they are the result of the conversion to digital format. ' Signed . HPc9 . O.i1t. c. Date . ~. C> . f\. ~ . ~? 1?