2-dimensional (2D) materials are fundamentally intriguing as their physical properties can vary considerably by not only their composition, but also their dimensionality i.e. the number of layers. This tunability makes them promising candidates for a range of advanced technologies and devices such as transistors, gas sensors and fuel cells. A potentially transformative application for 2D materials is in electrocatalysis, for the sustainable synthesis of chemicals from renewable energy sources. Platinum is the most commonly employed heterogeneous electrocatalyst for hydrogen evolution, however its scarcity and cost has triggered intense interest in alternative materials. Molybdenum disulphide (MoS2) is a transition metal dichalcogenide (TMD), which theoretically displays a similar Gibbs free energy of H adsorption to Pt, and experimentally the same order of magnitude turnover frequency.
For simple metals, models based on d-electrons exist which are extremely powerful in describing how catalytic behaviour is intimately linked with electron structure. The aim of this project is to extend this understanding further to TMD electrocatalysts using cutting-edge experimental and theoretical approaches. The successful candidate will have the opportunity to design and grow their own TMDs using a specially designed chemical vapour deposition system. These will be characterised by photoemission spectroscopy (UPS/XPS) and X-ray absorption spectroscopy (NEXAFS), allowing both the valence and conduction band electronic structures to be experimentally probed. Advanced operando capabilities available in the group can then be used to probe changes to the electronic structure when in the electrochemical reaction environment. The applicability of the d-electron model can be tested on these systems using quantum mechanical simulations, determining how the band structure is modified on introduction of adatoms to the material surface, and comparing this to experiment. The scope of the project should allow the successful candidate to decide how much weight is put on experimental and theoretical work. There are likely to be many opportunities to work at the nearby Diamond Light Source, the UK synchrotron, and to travel internationally to use other synchrotron facilities.
This EPSRC-funded 3.5 year DPhil in Materials DTP studentship will provide full fees and maintenance for a student with Home/Republic of Ireland or Islands fee status. The stipend will be at least £16,285 per year. Information on fee status can be found at http://www.ox.ac.uk/admissions/graduate/fees-and-funding/fees-and-other-charges.
Candidates will be considered in the November 2020 admissions field which has an application deadline of 13 November 2020 and, if the studentship is unfilled, in the January 2021 admissions field which has an application deadline of 22 January 2021.
Any questions concerning the project can be addressed to Dr Robert Weatherup (firstname.lastname@example.org) or Dr Rebecca Nicholls (email@example.com).
General enquiries on how to apply can be made by e mail to firstname.lastname@example.org. You must complete the standard Oxford University Application for Graduate Studies. Further information and an electronic copy of the application form can be found at https://www.ox.ac.uk/admissions/graduate/applying-to-oxford.