A critical comparative review of eco engineered versus conventional nanomaterials for PFAS detection and environmental remediation through green synthesis approaches

Abstract

Numerous reviews already summarize nanomaterial-based PFAS sensing and remediation; the distinct contribution of this review is a critical, comparative evaluation of eco-engineered nanomaterials-those synthesized through plant-extract-mediated, microbial, agro-waste-derived, and green-chemistry routes - specifically against their conventionally synthesized counterparts, across synthesis conditions, cost, scalability, degradation efficiency, and environmental safety, an axis of comparison largely absent from the existing PFAS-nanomaterial review literature (named comparisons are given in Sect. 1.1). Per- and polyfluoroalkyl substances (PFAS) are a large class of synthetic, fluorinated organic contaminants whose extreme persistence, wide industrial use, and resistance to conventional degradation have made them one of the most pressing water-quality concerns of the past decade. Existing treatment technologies - adsorption, membrane filtration, oxidation, and biological remediation - achieve only partial success, and each carries specific drawbacks such as incomplete degradation, secondary waste generation, high energy demand, and weak removal of short-chain PFAS. Nanomaterials have therefore attracted interest for their large surface area, tunable catalytic activity, and multifunctional performance. Beyond cataloguing individual studies, this review develops comparative summary tables for PFAS sensing platforms (electrochemical, optical/fluorescence, plasmonic/SERS, molecularly imprinted polymer, and biosensor-based) and for remediation technologies (conventional versus nanomaterial-assisted versus eco-engineered), explicitly weighing advantages, limitations, and field-readiness. It further examines degradation mechanisms underlying PFAS mineralization - reactive-oxygen-species generation, photocatalytic and electrocatalytic pathways, direct C–F bond cleavage, reductive defluorination, and hybrid catalytic systems - and discusses emerging directions including AI-assisted material design, machine-learning-guided optimization, hybrid multifunctional remediation platforms, life-cycle assessment, techno-economic analysis, field-scale implementation, and regulatory considerations. Overall, the review argues that eco-engineered nanomaterials offer a credible pathway toward lower-toxicity, lower-cost, and more environmentally compatible PFAS management, while identifying nanotoxicity, reproducibility, and scale-up as the principal barriers to be resolved before field deployment.