Molecular‑scale Ageing of Biochar in Soils: Evolution of Functionality, Performance, and Implications for Carbon Credits University of Edinburgh in United Kingdom

This fully funded PhD studentship at the University of Edinburgh offers an exciting opportunity to investigate the molecular-scale ageing of biochar in soils, focusing on the evolution of its functionality, performance, and implications for carbon credits. The project is hosted jointly by the School of Chemistry (Dr Valentina Erastova) and the School of Geosciences (Prof Saran Sohi), in collaboration with Black Bull Biochar, an industrial partner.

Biochar is increasingly recognised as a negative-emission technology due to its ability to stabilise carbon in soils over long timescales. However, current carbon accounting and certification frameworks often rely on bulk proxies that do not capture the molecular changes biochar undergoes during real soil ageing. This project aims to bridge this gap by combining experimental characterisation with advanced atomistic molecular modelling and simulation to build a mechanistic understanding of biochar ageing in soils.

The research will involve characterising fresh and soil-aged biochars to quantify changes in bulk composition and surface functional groups, developing and validating representative atomistic models, and using molecular simulations to probe how evolving functionality controls stability and interactions with key soil components. The project will also translate molecular insights into functionality-based indicators of durability and performance, supporting improved methodologies for high-integrity carbon removal credits and informing the rational design and certification of biochars for long-term soil use.

Key research questions include: how biochar surface chemistry evolves during soil ageing, how this affects durability and long-term carbon permanence, how ageing-driven changes alter interactions with soil components, and how molecular-scale descriptors can be translated into measurable indicators of biochar quality and durability. The project also explores the impact of functional evolution on biochar's performance as a soil amendment.

The successful candidate will receive interdisciplinary training in molecular simulation, environmental and soil chemistry methods, and industry-facing carbon accounting, including a placement with Black Bull Biochar. Applicants should have a strong degree in Chemistry, Materials Science, Chemical Engineering, Environmental/Geoscience, Physics or a related subject, and an interest in molecular-scale surface chemistry and sustainable technologies. Experience in molecular simulation, programming/data analysis, or HPC is advantageous but not essential.

The studentship is fully funded for 42 months, covering tuition fees and an annual stipend at the UKRI rate (£20,780 per annum for 2025-26) for candidates satisfying EPSRC residency criteria. The University of Edinburgh is committed to equality, diversity, and inclusion, with a range of initiatives to support a family-friendly working environment.

Applications are considered year-round until the position is filled. Before submitting your cover letter and CV, complete the School of Chemistry Equality, Diversity & Inclusion Form for 26/27 Entry and include the generated Receipt Number in your cover letter. For further details and to apply, visit the project page or contact Dr Valentina Erastova directly.