Researchers at the University of Bath have developed a cheap, carbon-based photocatalyst that can break down PFAS “forever chemicals” in water using only sunlight, according to findings published in RSC Advances (DOI: 10.1039/D5RA07284K) and announced on February 26, 2026. The work targets one of the most stubborn problems in environmental chemistry: PFAS molecules resist almost every conventional cleanup method because of their ultra-strong carbon-fluorine bonds. If the approach scales beyond the lab, it could offer communities a low-energy alternative to the costly filtration and incineration techniques that dominate PFAS remediation today.
In a summary of the research, the University of Bath explained that the new material is based on a porous organic framework that can harness sunlight to generate highly reactive species capable of attacking PFAS. Coverage on Phys.org emphasizes that the catalyst is built from inexpensive carbon-rich components rather than precious metals, and that it operates under conditions that are much closer to real-world water treatment scenarios than many earlier lab systems. The team’s early experiments focused on model PFAS compounds in controlled solutions, but the underlying chemistry is being positioned as a platform that could be tuned for a wide range of fluorinated pollutants.
How a Polymer Called PIM-1 Supercharges PFAS Destruction
The Bath team built its photocatalyst from readily available organic materials rather than expensive rare metals, a design choice that keeps production costs low. The key innovation is the addition of a polymer known as PIM-1, which the researchers say improves PFAS breakdown efficiency and allows the reaction to proceed at neutral pH, meaning the water does not need to be acidified or treated with harsh chemicals first. That neutral-pH capability matters because most real-world contaminated water, whether from municipal taps or industrial discharge, sits near a neutral range. A process that demands extreme acidity or alkalinity adds cost and complexity that can block adoption at treatment plants.
The study, led by electrochemistry professor Frank Marken at Bath, demonstrated that the carbon-based material absorbs sunlight and generates reactive species that attack carbon-fluorine bonds, releasing harmless fluoride ions as a byproduct. Tracking fluoride release is a standard way to confirm PFAS destruction. As UNSW researcher Dr. Sun explained in separate lab work on a related method, “We did this by following how much fluoride is released as those strong carbon-fluoride bonds are broken down,” because measuring fluoride directly shows how much of the PFAS have been degraded. By combining a high-surface-area organic scaffold with the gas-permeable PIM-1 polymer, the Bath group aims to maximize contact between PFAS molecules, dissolved oxygen and photogenerated radicals, pushing the reaction toward complete mineralization rather than partial breakdown.
The Sunlight Problem That Stalled Earlier Catalysts
A persistent gap in PFAS photocatalysis has been the mismatch between laboratory light sources and actual outdoor conditions. Many earlier experiments relied on UV-C light, a short wavelength that is abundant in lab lamps but almost entirely filtered out by Earth’s atmosphere. Research published in Chemical Engineering Journal on boron nitride–titanium dioxide composites documented this constraint, showing that UV-C lab successes do not reliably translate to outdoor performance because natural sunlight delivers mostly UV-A and visible wavelengths. That study provided quantitative degradation rates and half-lives under natural sunlight, establishing a benchmark that newer catalysts, including Bath’s carbon-based version, need to match or beat if they are to be deployed in open-air reactors or solar ponds.
Outdoor experiments have started to close that gap. In tests funded by the National Science Foundation, engineers placed water samples containing PFAS inside plastic bottles under natural sunlight and found that a boron nitride-titanium dioxide composite completed the degradation process in about nine hours. That timeline, while promising, still depends on consistent sun exposure, raising questions about performance in cloudy climates or during winter months. The Bath team’s purely organic approach may face the same seasonal limitations, though the university press release does not yet report equivalent outdoor timing data for its PIM-1 material. Scaling up will likely require reactor designs that capture and concentrate diffuse sunlight, or hybrid systems that supplement solar input with low-energy LEDs tuned to the catalyst’s absorption spectrum.
Why Regulators Are Pressing for Destruction, Not Just Filtration
Current PFAS cleanup in the United States relies heavily on granular activated carbon filters and ion-exchange resins, technologies that trap PFAS molecules but do not destroy them. The contaminated filter media then require disposal, often through high-temperature incineration, which itself raises concerns about incomplete combustion and airborne PFAS release. The U.S. Environmental Protection Agency has responded with a suite of actions including drinking water standards, CERCLA hazardous substance designation, and destruction and disposal guidance for PFAS. The agency’s health advisories for PFOA and PFOS in drinking water reflect extremely low concentrations that are considered protective, making capture-only strategies increasingly expensive to maintain as utilities chase parts-per-trillion targets.
Against that regulatory backdrop, any technology that can actually mineralize PFAS into fluoride and simple carbon fragments, rather than just moving the contamination from water to a landfill, carries obvious appeal. Separate research teams have explored parallel paths: a mesoporous FeNbO4 material showed promise as a stable, recyclable photo-Fenton catalyst for organic contaminant removal under solar light at near-neutral pH, and a hybrid nano catalyst combining an iron-based metal-organic framework with biowaste-derived graphene demonstrated effectiveness in water, as described by Sathish et al. in 2024. These converging results suggest that sunlight-driven destruction is not a single lab curiosity but a growing field with multiple viable material platforms that regulators and utilities could eventually evaluate side by side.
Opportunities and Obstacles on the Road to Real-World Use
For the Bath photocatalyst to move from benchtop to treatment plant, engineers will need to address several practical questions. One is longevity: PIM-1 and related organic frameworks must withstand repeated light cycles, fluctuating temperatures and exposure to complex mixtures of salts and natural organic matter without losing activity. Another is integration: utilities may prefer modular reactors that can bolt onto existing filtration trains, polishing water after activated carbon has removed bulk organics but before final disinfection. In that configuration, a solar-driven PFAS destruction step could reduce the volume of hazardous waste generated by filters and resins, easing long-term disposal burdens while keeping operating costs low.
There are also broader systems-level considerations. Because PFAS contamination often spans groundwater, surface water and industrial effluents, a successful technology portfolio will likely mix centralized and decentralized approaches. Carbon-based photocatalysts could be embedded in small-scale units for remote communities or industrial sites, while more robust inorganic systems such as boron nitride–titanium dioxide or FeNbO4 might anchor large municipal installations. The Bath team’s work underscores that cost-effective, metal-free materials can play a role in that mix, particularly in regions where sunlight is abundant and energy prices are high. As more datasets emerge on performance under real sunlight, catalyst recyclability and byproduct monitoring, regulators will be better positioned to decide when “destroyed” in the lab truly means destroyed in the environment.
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*This article was researched with the help of AI, with human editors creating the final content.
