Catalyst That Destroys ‘Forever Chemicals’ with Sunlight, Improved
Summary
Michael Wong and his students made the surprising discovery in 2020 that boron nitride, a commercially available powder that’s commonly used in cosmetics, could destroy 99 percent of PFOA, or perfluorooctanoic acid, in water samples within just a few hours when it was exposed to ultraviolet light with a wavelength of 254 nanometers. So Wong and study co-lead authors Bo Wang, Lijie Duan, and Kimberly Heck decided to create a composite of boron nitride and titanium dioxide that married the best features of the individual catalysts. By analyzing photocurrent response measurements and other data, Wong’s team learned how its semiconductor composite harvested UV-A energy to break apart PFOA molecules in water. Some US states have set limits on PFOA contamination in drinking water, and in March 2021 the Environmental Protection Agency announced plans to develop federal standards. PFOA is one of the most prevalent PFAS (perfluoroalkyl and polyfluoroalkyl substances), a family of compounds developed in the 20th century to make coatings for waterproof clothing, food packaging, and other products.