Experimental study on pure Brookite synthesis method.
Nufrizal Abu Bakar.
Date of Issue2009
School of Materials Science and Engineering
Brookite is a polymorph of titanium dioxide along with anatase and rutile. The latter two have been extensively researched on as a photocatalyst. Synthesis of brookite is relatively difficult as compared to anatase or rutile due to its metastable phase and converts readily to the other polymorphs. Therefore, little study has been done on its photocatalytic properties. Several differing and contradicting methods have claimed to produce singlephase brookite through varying techniques, which can be broadly categorized into hydrothermal and thermolysis methods. The objective of this study is to identify and synthesize single-phase pure brookite by hydrothermal or thermolysis methods, or both. Synthesis parameters have been altered to obtain the single-phase brookite. The powders were analysed through means of X-Ray diffraction and the Rietveld refinement. While the various synthesis methods did not result in single-phase brookite, varying weight percent of brookite were present, which allowed comparison of the various methods. The project identified several key factors definite to influence brookite yield. Hydrothermal methods using acidic or slightly alkaline medium were able to give higher brookite yield. Extended aging period of over 60 hours allowed for brookite formation as well. Refining the process in Experiment 7 to obtain single-phase brookite through changing the parameters of by peptization to separate brookite from the other phases is also recommended. Refining the synthesis parameters is recommended for future works to identify the optimal characteristics to create an improved brookite photocatalyst.
Final Year Project (FYP)
Nanyang Technological University