Materials scientists developed a hybrid, metal-free material that uses light to break down a range of pollutants in water, including per- and polyfluoroalkyl substances (PFAS). The design joins a porous covalent organic framework (COF) with a thin film of hexagonal boron nitride (hBN) to form a connected surface with high area for light-driven reactions.
The Rice team grew the COF directly on the hBN film and used defect engineering — etching microscopic scratches into the hBN — so the COF could anchor and grow. This interface directs light-energized electrons and holes in different directions, which helps the photocatalytic breakdown of contaminants.
Researchers tested the material in vertical and horizontal flowing-water reactors that mimic treatment facilities. It performed consistently over repeated cleaning cycles and maintained its structure and stability. Additional researchers from Rice and the University of Florida contributed.
Difficult words
- pollutant — a harmful substance in air or waterpollutants
- covalent organic framework — a porous material made of linked organic molecules
- hexagonal boron nitride — an inorganic material with a hexagon layer structure
- porous — having many small holes or spaces inside
- defect engineering — making small controlled flaws to change material properties
- photocatalytic — causing chemical reactions when exposed to light
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Discussion questions
- How could light-driven, metal-free materials change water treatment at local facilities?
- What are possible benefits of a material that stays stable over repeated cleaning cycles?
- Would you trust water treated with new materials like this? Why or why not?
