Atomically Thin Materials Emerge as Powerful Weapons Against Forever Chemicals

Per- and polyfluoroalkyl substances, the notorious family of synthetic chemicals known as PFAS or “forever chemicals,” have earned their ominous nickname for good reason. Their carbon-fluorine bonds are among the strongest in organic chemistry, rendering them virtually indestructible in the environment and stubbornly resistant to conventional water treatment. These compounds, used for decades in nonstick cookware, waterproof textiles, firefighting foams, food packaging, and countless industrial processes, now contaminate drinking water supplies, rivers, sediments, and even remote Arctic ecosystems across the globe. A comprehensive new review published in Environmental Science and Pollution Research examines a promising frontier in the battle against these persistent pollutants: two-dimensional materials, atomically thin sheets whose extraordinary surface chemistry may finally offer an efficient, scalable way to strip PFAS from contaminated water.

The review, led by Taghreed M. Adnan of Al-Karkh University of Science in Baghdad together with colleagues from institutions in Iraq and Pakistan, systematically evaluates seven classes of two-dimensional adsorbents: graphene and its derivatives, MXenes, two-dimensional metal-organic frameworks, covalent organic frameworks, layered double hydroxides, phosphorene, and hexagonal boron nitride. Rather than relying on incineration or energy-intensive destruction technologies, which remain costly and difficult to deploy at municipal scale, the adsorption approach captures PFAS molecules directly from water, concentrating them onto a solid material that can then be managed or regenerated. The central question the authors address is which of these ultrathin materials performs best, and why.

The answer, according to the accumulated literature, is graphene. Graphene and its oxidized cousin, graphene oxide, consistently rank among the top performers for PFAS capture, and the reasons are rooted in fundamental materials science. A single gram of graphene can present thousands of square meters of surface area, providing an enormous number of binding sites. More importantly, the surface chemistry of graphene oxide can be precisely tuned: researchers can graft amine groups, fluorine moieties, polyethyleneimine, or alkyl amines onto the nanosheets to create electrostatic and hydrophobic attractions tailored to the long, water-repelling fluorinated tails of PFAS molecules. Molecular dynamics simulations have confirmed that functionalization dramatically strengthens the interaction between the nanosheet and perfluorooctanoic acid and perfluorooctanesulfonate, the two most studied legacy compounds.

Experimental studies bear this out. Amino-functionalized graphene oxide aerogels have shown high removal efficiency for PFOA across varying pH conditions and water matrices, while fluorinated graphene oxide combined with polyethyleneimine has been assembled into three-dimensional porous platforms capable of capturing PFAS alongside pharmaceutical toxins and waterborne pathogens. Recent work has even pushed the concept to remarkable extremes: graphene oxide engineered with an ultrathin adlayer of roughly one nanometer achieved near-instantaneous removal of multiple PFAS species, suggesting that carefully designed interlayer galleries can act as molecular traps. Electrosorption approaches, in which an alternating electric field drives PFAS onto and off of graphite or graphene-based electrodes, add a further dimension of control, enabling reversible capture and release that could simplify adsorbent regeneration and reduce operational costs.

Close behind graphene, the review identifies MXenes as the second-best-performing family, despite a comparatively limited number of published studies. MXenes are two-dimensional transition metal carbides and nitrides, typically produced by etching aluminum from layered ceramic precursors such as titanium aluminum carbide. The resulting sheets, exemplified by Ti3C2Tx, carry a rich complement of surface terminations including hydroxyl, oxygen, and fluorine groups, which give the material both structural and electrochemical stability and a versatile charge landscape for binding anionic PFAS. Studies comparing MXenes against commercial anion-exchange and PFAS-specific resins found the nanosheets competitive even for zwitterionic PFAS, a subclass that many conventional adsorbents struggle to capture. MXene-based electrodes have also demonstrated effective electrosorption of PFOA, and delaminated titanium carbide MXenes have shown that surface chemistry, not merely surface area, governs the adsorption mechanism and overall removal efficiency.

The engineered porosity of two-dimensional metal-organic frameworks and covalent organic frameworks gives these materials a distinct advantage of a different kind. MOFs are crystalline lattices of metal nodes connected by organic linkers, while COFs are purely organic frameworks stitched together by strong covalent bonds; both can be designed with precisely sized pores and functionalized internal surfaces. Mesoporous MOFs have been shown to sorb perfluorooctanesulfonate efficiently from aqueous solutions, and zirconium-based MOFs, particularly those decorated with free hydroxyl groups, have achieved enhanced PFOA uptake, with crystal topology and interior surface functionality playing decisive roles. On the COF side, amine-functionalized frameworks have successfully removed GenX and other perfluorinated alkyl substances from water, while cationic COFs exploit electrostatic attraction to cooperative effect, in one case simultaneously serving as fluorescent sensors that signal PFOA capture in real time.

Layered double hydroxides operate on a simpler but elegant electrostatic principle. These positively charged metal hydroxide layers, built from combinations such as magnesium-aluminum or zinc-aluminum, present an inherently favorable surface for the negatively charged heads of PFAS molecules. Studies of Mg-Al and Zn-Al LDHs, including hydrotalcite, have demonstrated strong adsorption of PFOA and the industrial substitute F-53B, with mechanisms encompassing surface adsorption, interlayer anion exchange, and in some cases subsequent thermal decomposition of the captured precipitates. Organic functionalization of the LDH interlayers further boosts performance, and research into adsorbent aging and thermal regeneration is clarifying how these materials can be cycled repeatedly in real treatment trains. Hexagonal boron nitride, meanwhile, brings a graphene-like layered architecture together with exceptional chemical and thermal stability; porous h-BN has even been used to adsorb PFOS and PFDA from water and then destroy the captured molecules through simultaneous thermal decomposition, regenerating the adsorbent in the same step.

The most enigmatic entry in the review is phosphorene, the two-dimensional form of black phosphorus. Although far less studied than the other materials, phosphorene possesses a highly reactive surface owing to its elevated electron density, and density functional theory calculations have shown that strain engineering can substantially modulate PFOS adsorption on both pristine and defected phosphorene sheets. This tunability hints at significant untapped potential, though the material’s sensitivity to oxidation in water remains a practical hurdle that future work must address. Taken together, the comparative analysis makes clear that no single material is a universal solution: performance depends on PFAS chain length, water chemistry, competing organic matter, ionic strength, and the ever-growing diversity of short-chain and replacement compounds entering the environment.

What emerges from this synthesis is a roadmap. Graphene offers unmatched surface area and chemical versatility; MXenes add electrochemical robustness and electrosorption capability; MOFs and COFs contribute designer porosity and molecular recognition; LDHs deliver charge-matched capture with regeneration options; h-BN combines stability with the possibility of integrated adsorption and destruction; and phosphorene beckons as a reactive, strain-tunable frontier. The authors emphasize that translating these laboratory successes into real-world water treatment will require advances in synthesis scalability, adsorbent cost, regeneration cycles, and validation across the complex matrices of actual drinking water and wastewater. Yet the trajectory is unmistakable. As regulators worldwide tighten PFAS limits and public concern over forever chemicals intensifies, these atomically thin materials, each just one or a few atoms thick, are positioning themselves as some of the most powerful tools yet devised for cleaning up one of the most stubborn pollution problems of the modern age.

Subject of Research: Two-dimensional nanomaterials for the adsorption and removal of PFAS from contaminated water

Article Title: Emerging two-dimensional materials in PFAS remediation: a comprehensive review of adsorption mechanisms and efficiency

Article References: Adnan, T. M., Hasan, M. B., Jweeg, M. J., Hamad, A. J., Salih, S., Ammory, Z. H., Tariq, M. F., & Kadhom, M. (2026). Emerging two-dimensional materials in PFAS remediation: a comprehensive review of adsorption mechanisms and efficiency. Environmental Science and Pollution Research. https://doi.org/10.1007/s11356-026-38227-4

Image Credits: AI Generated

DOI: 10.1007/s11356-026-38227-4

Keywords: PFAS, forever chemicals, two-dimensional materials, graphene, MXenes, metal-organic frameworks, covalent organic frameworks, layered double hydroxides, hexagonal boron nitride, phosphorene, adsorption, water treatment