Wastewater treatment facilities and chemical manufacturing plants may soon have a new nanocatalyst-based tool at their disposal for cleaning up the lingering contamination posed by “forever chemicals” — per- and polyfluoroalkyl substances (PFAS). The aqueous electrocatalytic process developed at the University of Rochester is based on the use of laser-made nickel-iron alloy-layered double hydroxide nanocatalysts.

Pulsed lasers are applied to control the surface chemistry of the catalysts, which are then attached to hydrophilic carbon paper anodes to form an inexpensive substrate with a high surface area. This treatment system was tested for the electrocatalytic defluorination of perfluorooctane sulfonate (PFOS), a PFAS that is now banned but still persisting in water supplies due to its former use in the manufacture of stain-resistant products. Complete defluorination was demonstrated by pulsed electrolysis of PFOS in aqueous lithium hydroxide solution assisted by ultraviolet light irradiation.

The treatment system described in the Journal of Catalysis successfully decontaminated a PFOS concentration of 27 ppm, which is relevant for environmental water pollution remediation. Electrocatalytic defluorination within the anode microenvironment was also confirmed for perfluorooctanoic acid.