E-Thesis 71 views
Atomistic Modelling of Nitrogen-rich Biobased Carbon Materials / ANNA HERRERA
Swansea University Author: ANNA HERRERA
DOI (Published version): 10.23889/SUThesis.67953
Abstract
Chars from pyrolysis and hydrothermal processing of biomass are potential waste-to-material valorisation candidates for being a heteroatom-rich and porous carbon materials. They are suitable as electrodes in energy storage, and as biobased fertilisers in soil amendments. In energy storage, biomass’...
| Published: |
Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Martin-Martinez, F.; Mabbett, I.; and Vidal-Daza, I. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa67953 |
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| Abstract: |
Chars from pyrolysis and hydrothermal processing of biomass are potential waste-to-material valorisation candidates for being a heteroatom-rich and porous carbon materials. They are suitable as electrodes in energy storage, and as biobased fertilisers in soil amendments. In energy storage, biomass’ heteroatoms are incorporated into the electrode’s structure, increasing wettability, and promoting electrode-electrolyte interactions. In agriculture, nitrogen functionalities and high porosity allow for essential elements adsorption and water retention, therefore enhancing the plant uptake. This thesis uses atomistic modelling of char graphitic surfaces (both finite and periodic) with different surface features and performs density functional theory calculations to achieve a better understanding of the interactions between biobased chars and relevant adsorbates in energy storage and soil remediation. The effect of different nitrogen functional groups in the graphitic structure was investigated, along with the effect of surface curvature and radius, and the effect of spin multiplicity of certain transition metal species.The methodology and codes developed in this thesis should allow the study of any adsorption system provided a surface and an adsorbate. The results indicate that the interactions between species and biobased chars strongly depend on the surface curvature and nitrogen content – but also on the spin multiplicity of the transition metal species, which in most cases evolves into an open shell electronic structure to maximise coordination with the aromatic system. The findings provide additional fundamental knowledge to help with the development of fit-for-purpose biobased chars for energy storage with a tailored nanostructure, and biobased fertilisers, among other potential applications. Based on this findings, processing conditions can be selected to promote those chemical and structural features highlighted by the theoretical studies presented here. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Biomass, biochar, hydrochar, materials science, energy storage, water retention, atomistic modelling, density functional theory, molecular dynamics, computational chemistry |
| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC PhD Scholarship |