Ultra-high selective adsorbents for per- and polyfluoroalkyl substances (PFAS) destruction: Bridging the gap between adsorption and catalytic degradation for excellent performance in persistent environmental contaminants
Tanusha Devi Elan Solan, Noorashikin Md Saleh, Shabbah Begum, Farhanini Yusoff
Abstract
• Hybrid systems integrate adsorption & catalysis for PFAS destruction. • MOFs/COFs use confinement/proximity effects for rapid PFAS degradation. • Destruction method eradicates secondary waste and targets short-chain PFAS. • Future work uses AI/ML and XAFS to optimize material design and cost. • Integrative strategy supports UN SDGs 6 (Clean Water) and 9 (Innovation). Per- and polyfluoroalkyl substances (PFAS) emerged as persistent environmental pollutants, posing substantial challenges due to robust carbon-fluorine (C–F) bonds and their resistance to conventional treatment. While conventional adsorption effectively concentrates PFAS, it results in detrimental secondary waste requiring costly and energy-intensive off-site treatment. This review addresses this critical gap by exploring the innovative integration of adsorption and catalytic degradation within hybrid systems. This novel approach aims to capture and simultaneously degrade PFAS in situ , thereby achieving full mineralization and minimizing secondary pollution. This paper highlights the design principles of advanced materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), emphasizing their structural tunability, high surface area, and precise functional group incorporation, facilitating both selective adsorption and catalytic destruction. Key findings from the literature include the demonstration of pore confinement-enhanced catalytic reactions, the elucidation of synergistic adsorption–degradation mechanisms, and performance comparisons of various defluorination pathways. Despite these breakthroughs, significant challenges persist, including maintaining selectivity in complicated matrices, limiting catalyst deactivation owing to organic fouling, and scaling up economically. To address these, future research directions must focus on developing size-exclusion coatings, employing UV/ozone pretreatment to decrease fouling, and undertaking detailed cost evaluations comparing hybrid and single-function materials. Furthermore, the review underlines the substantial potential of sophisticated characterisation techniques, including in situ X-ray Absorption Fine Structure (XAFS) spectroscopy and the application of Artificial Intelligence/Machine Learning (AI/ML) for high-throughput screening and optimization. This review provides a critical framework for interdisciplinary collaboration to accelerate the development and implementation of hybrid systems, effectively bridging the gap between concentration and destruction for sustainable PFAS remediation, thus directly supporting SDGs 6 and 9.