Sunlight-Activated Catalysts Improve Wastewater Pollutant Removal

Researchers at the University of Birmingham have demonstrated a solvent-free mechanical method for producing solar-activated 2D catalysts capable of degrading persistent organic pollutants in industrial wastewater — addressing a key scalability barrier in photocatalytic treatment technology.

The process, published in npj 2D Materials and Applications (DOI: 10.1038/s41699-026-00690-5), uses high-intensity turbulent shear stresses to exfoliate molecular-thin sheets of graphitic carbon nitride (g-C3N4) and molybdenum disulfide (MoS2) and assemble them into heterostructures with tunable photoelectronic properties — all in water and without toxic solvents.

According to the research, the mechanical treatment produces ultra-thin layers with increased surface area and atomic edge creation while preserving electronic structure and charge transport properties essential for photocatalytic activity. Peak performance is reportedly achieved after just 10 minutes of mechanical treatment.

Testing against three model pollutants — Indigo Carmine, Rhodamine B and Acid Red 266 — showed degradation performance up to 2.5 times higher than bulk raw material. Notably, Acid Red 266 contains carbon-fluorine bonds, among the most chemically persistent structures in industrial effluent. Degradation products are carbon dioxide, water and inorganic salts.

"A major roadblock to pursuing this approach has been the lack of sustainable and scalable ways of making catalysts in a format that enables efficiency in the chemical reaction,"  Jason Stafford, who led the research, said in a statement. "We have shown this is possible, and are confident that the method could be used to produce photocatalysts at an industrial scale."

According to the press statement, a patent application has been submitted and the research team is seeking commercial partners for licensing or development in advanced materials and wastewater treatment applications.