Rational design of photocatalysts for selective reduction and oxidation

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Aim: Selective reduction and oxidation of feedstock to high value chemicals is a big challenge in catalysis, which highly depends on the efficiency of the catalyst and always requires harsh experimental conditions. The project targets to develop robust photocatalysts to highly selectively reduce water to hydrogen fuel and/or oxidise biowaste eg. Glycerol to high value chemicals operated under mild experimental conditions. Objectives: A grand challenge facing our society today is energy security. Economical and robust technologies for renewable and clean energy synthesis are highly sought-after. In order to mitigate environmental and energy issues caused by mass consumption of exhaustible fossil fuels, the importance of developing alternative renewable and economically viable energy sources has been widely recognized. On the other hand, some cheap but versatile molecules, like glycerol, can be transformed to different value-added fine chemicals and products. Under sunlight, electron-hole pairs generated in semiconductors could selectively reduce water into hydrogen and selectively oxidise biowaste to produce valuable fine chemicals used in the chemical and pharmaceutical industry. Development of novel photocatalysts with high selectivity, efficiency, scalability, and cost-competitiveness is therefore targeted for hydrogen fuel and fine chemicals production in the project. The fundamental understanding will also be explored in order to further improve its efficiency. The objectives include (1) design and synthesis of hydrogen evolution photocatalysts for efficient light absorption and water reduction; (2) design and synthesis of selective oxidation photocatalysts for fine chemicals production; (3) using appropriate solid medium for charge transfer to generate hydrogen and fine chemicals simultaneously.Methodology: In this project, new photocatalysts will be rationally designed and synthesised by polymerisation, chemical deposition and microwave-hydrothermal method. Then they will be fully characterised by XRD, Raman, NMR, BET, UV-vis spectra etc. The photocatalysts will be analysed to assess their efficiency, selectivity and stability by my reaction system. The electron transfer mechanism in the photocatalysts will be studied by time resolved spectroscopies in collaboration with one member in the group, which will be fed back to photocatalysts selection and structure optimisation in order to further improve efficiency. This is within the domain of catalysis/photocatalysis.