For all the recycling bins and good intentions in the world, most plastic still ends up incinerated, in landfill, or drifting through waterways as microplastic fragments. A team at the University of Waterloo in Ontario, Canada, wanted to try a different question: instead of how to dispose of plastic, what if the goal was to turn it into something worth having?
Their answer is a photocatalytic system — a solar-powered chemical process — that converts common plastic waste directly into acetic acid, the compound that gives vinegar its characteristic sharpness and that underpins a wide range of industrial applications, from food preservation to the manufacture of textiles and pharmaceuticals. It is, in other words, not a waste product. It's a commodity.
The inspiration came from fungi, which break down tough organic materials through a stepwise chain of enzyme reactions. The Waterloo team engineered a synthetic equivalent: iron atoms — present at just 0.5% by weight — embedded in a carbon nitride framework that, when exposed to sunlight, triggers a cascade of reactions that progressively dismantles plastic polymers into something useful.
What makes the process particularly promising is its versatility. It works in water, produces no additional carbon dioxide, and handles a broad range of plastics — PVC, polypropylene, polyethylene, and PET — remaining effective even when these are mixed together, as they almost always are in the real world. The research, led by PhD student Wei Wei under Professor Yimin Wu, is published in the journal Advanced Energy Materials.
Scaling it from lab bench to industrial reality remains the central challenge. But the principle is now established: one of the world's most persistent pollutants can, with the right catalyst and a patch of sunlight, be turned into something worth selling.