| Summary: | <p>Water contamination is a severe problem faced by the whole world. With the rapid growth in global population, this problem is even worsening. Fullerene and TiO2 are promising photocatalysts for water purification owing to their intrinsically high photocatalytic activity. Yet, a lot of weaknesses (e.g. large bandgap of TiO2, hydrophobicity of fullerene, etc.) unfortunately inhibit them from fulfilling their potential in water purification. In this thesis, different strategies were designed to synthesize and functionalize various carbon nanomaterials. Afterwards, these specifically designed and prepared carbon nanomaterials were employed to overcome the intrinsic weaknesses of both fullerene and TiO2. Great improvement in photodynamic performance was witnessed in both photocatalysts. Their potential in water purification was hence proved.</p>
<p>Firstly, C60 was functionalized with pyrene moieties via Prato Reaction. The as-prepared C60 derivatives exhibited clearly improved absorption in visible range. The apparent photodynamic activity of these C60 derivatives in both organic and aqueous solutions suggested their potential application in water purification.</p>
<p>Secondly, an eco-friendly way to harvest multi-layer graphene with low defect density and low oxidation degree was established. Moreover, a modified Hummers Method for controllably oxidizing graphene towards different oxidation degree was developed. The combination of these two designs enabled the finding of the graphene material with the optimal oxidation degree, which not only can boost the synergistic effect between the substrate and the photocatalyst in composites, but also can maintain original properties of the graphene material to the greatest degree.</p>
<p>Subsequently, a facile method for producing Fullerene/Graphene and Fullerene/Graphene Oxide composites was established. The strong interaction within composites between fullerene and graphene substrates was identified by Raman. The great improvement in fullerene’s photocatalytic activity in these composites was witnessed in photodynamic test. Fullerene’s excellent photodynamic performance, which was much better than that of commercial anatase TiO2, further confirmed its application potential in water purification.</p>
<p>Finally, different composites between graphene materials and anatase TiO2 were prepared by three strategies. Photocatalysts with enhanced photocatalytic activity were successfully synthesized and several important factors which control the final photodynamic performance of materials were identified.</p>
<p>Overall, good progress was made in both the material preparation and the understanding of different underlying factors limiting the photodynamic performance of photocatalysts. This work brings the application of fullerenes and TiO2 for water purification, one step closer.</p>
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