Waste treating waste
Waste treating waste: sunlight-driven photocatalysts from biomass residues and earth-abundant minerals for off-grid water remediation and solar hydrogen
Lead Supervisor: Flurin Eisner
Degree Programme: PhD in Materials Science at the Centre for Sustainable Engineering
Co-Supervisor:
Roberto Volpe (School of Engineering and Materials Science)
Project Description
Could yesterday’s crop and food waste clean tomorrow’s drinking water and make fuel, using nothing but sunlight? More than two billion people lack safely managed drinking water. In rural and under-resourced regions, untreated wastewater carries pathogens, dyes, pesticides and pharmaceuticals straight into the rivers and wells that communities rely on. Conventional treatment needs grid power, chemicals and trained operators, so it rarely reaches the people who need it most. Photocatalysis offers another route: simple nanoparticles dispersed in wastewater use sunlight to break down organic pollutants and kill microbes.
In this project, we will go a step further. You will make powerful, low-cost photocatalysts from things we normally throw away, turning agricultural and food residues, such as pollen, husks and peels, into porous carbon scaffolds. You will then pair them with light absorbers made from earth-abundant, non-toxic semiconductors such as carbon nitride and iron oxides. The carbon acts as a sponge, holding pollutants right next to the light absorber so a single material can trap and destroy them. The same light-driven reactions can turn pollutants into a resource, using them to produce green hydrogen while the water is cleaned.
You will: • Design and synthesise waste-derived carbon/metal-oxide composites, engineering band gaps, interfaces and porosity to absorb visible light and separate charges efficiently. • Uncover how they work, using spectroscopy, electron microscopy and photoelectrochemical measurements to track charge carriers and the reactive oxygen species that destroy pollutants. • Measure degradation kinetics and quantum efficiencies, and build a simple solar flow reactor to test them on real wastewater under natural sunlight, showing they are durable, reusable and free of toxic leaching, and quantify any hydrogen co-produced. • Work with communities to explore what it would take for this technology to be adopted, so your research is shaped by the people it aims to serve.
You will join two complementary groups at Queen Mary. Flurin Eisner’s group brings expertise in photocatalysis and light-absorbing materials. Roberto Volpe’s group specialises in turning biomass into functional porous carbons that host catalytic sites. The project spans materials science, chemistry and chemical engineering. You will be based in the Centre for Sustainable Engineering in the School of Engineering and Materials Science, working in state-of-the-art facilities such as the new Green Energy Hub. As part of the Living with Waste CDT, you will join a cohort working across the sciences, engineering, humanities and social sciences, building skills and networks that reach well beyond a single discipline.
What we're looking for in a student
We are looking for an enthusiastic, curious student who is excited to spend time in the lab and wants their research to make a real-world difference. Applicants should hold, or expect to obtain, a good degree in chemistry, physics, materials science or engineering, or a closely related subject. Hands-on laboratory experience is an advantage, but prior experience in photocatalysis is not required. You will receive training in materials synthesis, spectroscopy, electron microscopy, photoelectrochemistry and reactor design, as well as in community engagement through the Living with Waste CDT cohort programme. You will have access to state-of-the-art facilities in the Centre for Sustainable Engineering and the new Green Energy Hub, including nanomaterials fabrication and materials characterisation suites.
Key words: Photocatalysis; Water treatment; Waste valorisation; Solar fuels; Nanomaterials