Emerging contaminants such as pharmaceutical residues are increasingly detected in water bodies, and compounds such as Iopamidol, a widely used iodinated X-ray contrast agent, are particularly challenging because they are persistent, difficult to remove by conventional wastewater treatment, and can lead to the formation of toxic disinfection by-products. Visible-light photocatalysis offers a sustainable treatment route, but commonly used graphitic carbon nitride (g-C₃N₄) suffers from limited surface area, suboptimal visible-light absorption, and inefficient charge separation, which restrict its photocatalytic performance.
Our research develops sodium and copper co-doped graphitic carbon nitride (NaCu-g-C₃N₄) photocatalysts for the visible-light degradation of persistent water contaminants. By engineering the electronic structure and surface properties of carbon nitride through Na/Cu co-doping, we enhance visible-light absorption, reduce the bandgap, improve charge transfer, and increase the surface area available for photocatalytic reactions. Comprehensive materials characterization is used to relate structural and electronic modifications to photocatalytic activity and identify the factors governing catalyst performance.
Photocatalytic and mechanistic studies show that the optimized NaCu-g-C₃N₄/H₂O₂ system achieves efficient degradation of Iopamidol under visible light, outperforming pristine carbon nitride. These insights support the development of low-cost, visible-light-active photocatalysts for sustainable water treatment and the removal of emerging contaminants.

Liquid organic hydrogen carriers (LOHCs) offer a promising route for storing and transporting hydrogen using liquid molecules that can be reversibly hydrogenated and dehydrogenated. Alcohol and polyol-based LOHCs are particularly attractive because they can be derived from renewable resources and potentially store hydrogen at useful densities. However, current catalysts often require high precious-metal loadings and can promote unwanted C–O and C–C bond cleavage, reducing selectivity and carrier lifetime. Developing efficient, selective and lower-cost catalysts is therefore essential for practical LOHC systems. Our research develops catalysts for the reversible hydrogenation and dehydrogenation of alcohol and hydrocarbon based LOHCs, enabling efficient hydrogen storage and release while minimising unwanted bond cleavage and catalyst deactivation. By combining systematic catalyst design with kinetic, isotopic and spectroscopic studies, we investigate elementary reaction steps, including the role of hydrogen radicals and background C–H scrambling, to identify the active sites and pathways that control performance. These insights inform the development of efficient, selective and low-precious-metal catalysts. Process and energy modelling assesses heat and energy requirements, efficiency and scalability, connecting catalyst performance with practical LOHC-based hydrogen storage systems.

Plastics derived from vinyl and olefinic monomers represent a major component of global plastic waste, yet effective recycling routes for these materials remain limited. Chemical recycling offers the potential to recover high-value monomers from waste plastics, enabling the production of new materials without loss of performance while also tolerating contamination and mixed-feed waste streams that are challenging for conventional mechanical recycling.

However, recycling vinyl plastics such as polystyrene, PMMA (Perspex®) and PVC typically relies on thermolysis above 400°C, resulting in high energy demands and poor selectivity. The Husband, Freakley and Davidson groups have recently developed a scalable depolymerisation method for PMMA that operates below 200°C. The approach uses light to generate radicals from the photolysis of substituted aromatics. These radicals facilitate Hydrogen Atom Transfer (HAT) to generate polymer radicals, which under favourable thermodynamic conditions, trigger selective depolymerisation back to monomer.