There is a pressing need to improve the sustainability of chemical synthesis using catalysis powered by renewable sources of energy. Photocatalysis aims to use abundant solar energy to drive chemical reactions. Heterogeneous photocatalysis is particularly attractive because product separation is straightforward. Various inorganic photocatalysts have been shown to absorb light and subsequently promote catalytic redox reactions via the formation of organic radical intermediates. Photocatalytic reactions are typically developed from screening a large number of reactions using complex mixtures of additives that are often required to improve reaction rate and selectivity. However, there is a significant lack of understanding of reaction mechanisms and role(s) of catalyst and additives which limits their rational development. Investigation of key mechanistic steps will help to provide guiding principles for the development of new reactions. Mechanistic steps include substrate binding to the photocatalyst, the oxidation and reduction of substrates to produce radical species, and the reaction of radicals to form products. There is an exciting opportunity to explore details of how these reactions occur and gain understanding that would be of more general use to the chemical community. This project benefits from the joint expertise of the Douthwaite and Chechik groups which encompasses inorganic materials chemistry, catalysis, and mechanistic organic radical chemistry and is a great opportunity to contribute to a rapidly developing area of sustainable chemistry.
You will measure the energetics of binding between substrates used for C-C and C-X coupling and photocatalysts in the dark and under light irradiation. This information will help to understand the role of substrate binding on reaction rate and selectivity. You will measure the generation of radicals under pulsed and continuous illumination using EPR methods. This information will help understand the role of homogeneous vs heterogenous radical chemistry. Finally, radical quenching to produce product will be studied using a combination of reactivity studies and EPR. This information will help to particularly understand the fate of intermediate radicals and reaction selectivity. Throughout, the focus will be on scientific discovery and development of semi-quantitative mechanistic understanding that will guide reaction discovery.
The Douthwaite and Chechik groups are co-located in a state-of-the-art laboratory with communal lab and office space providing a vibrant learning environment. You will become part of two research teams which complementary expertise to support your project. With the Douthwaite group you will be supported to synthesise and characterise photocatalysts, and perform photocatalytic reactions. With the Chechik group you will be supported in radical chemistry and EPR spectroscopy. Regular informal meetings between you, Douthwaite and Chechik will support project development.
There is little mechanistic understanding of the complex systems that are currently being developed for photocatalytic synthesis. The development of guiding principles will help to increase rate and selectivity whilst reducing or eliminating the need for some additives that add to costs and reduce sustainability. This would be a significant contribution to the field.
Training: You will develop skills in a wide range of specialist experimental and analytic techniques, and wider transferrable skills. These will include synthesis of inorganic materials and simple organic compounds, catalytic methodologies and characterization techniques including SEM/TEM, PXRD, UV-Vis, NMR, GC, HPLC, MS and EPR. Both groups can offer further development opportunities as part of the wider inorganic and organic chemistry sections which foster an inclusive environment for scientific discussion across a broad portfolio of modern chemistry.
All Chemistry research students have access to our innovative Doctoral Training in Chemistry (iDTC): cohort-based training to support the development of scientific, transferable and employability skills: https://www.york.ac.uk/chemistry/postgraduate/cdts/
The Department of Chemistry holds an Athena SWAN Gold Award and is committed to supporting equality and diversity for all staff and students. The Department strives to provide a working environment which allows all staff and students to contribute fully, to flourish, and to excel: https://www.york.ac.uk/chemistry/ed/.
For more information about the project, click on the supervisor's name above to email the supervisor. For more information about the application process or funding, please click on email institution
This PhD will formally start on 1 October 2022. Induction activities may start a few days earlier.
To apply for this project, submit an online PhD in Chemistry application:
You should hold or expect to achieve the equivalent of at least a UK upper second class degree in Chemistry or a related subject.