Strategically Functionalised Graphene Surfaces for the Selective Removal of Polycyclic Aromatic Hydrocarbons From...

This review critically evaluates the recent progress in selectively functionalised graphene and its derivatives for the efficient removal of polycyclic aromatic hydrocarbons (PAHs) from aquatic systems. It begins by outlining the structural, electronic, and surface properties of graphene and its derivatives that underpin their environmental relevance. Functionalisation strategies are categorised into covalent and noncovalent approaches. Covalent modification introduces hydroxyl, epoxy, carboxyl, diazonium, nitrene, and peroxide groups onto the graphene lattice, enabling precise control over surface chemistry and reactivity. Noncovalent functionalisation, based on hydrogen bonding, electrostatic interactions, and π-π stacking, preserves the sp² carbon framework while tailoring their interfacial affinity. Herein authors highlight how engineered surface chemistry enhances PAHs adsorption, a surface-dominated process governed by porosity, surface energy, and specific molecular interactions. Notably, graphene oxide functionalised with 9-aminoanthracene achieved removal efficiencies of 94%, 79%, and 74% for naphthalene, acenaphthylene, and phenanthrene, respectively, with sustained performance over repeated adsorption-desorption cycles. Owing to their hydrophobic and planar structures, PAHs strongly interact with graphene via π-π stacking. As carcinogenic and mutagenic priority pollutants, PAHs present serious environmental risks. The article further integrates the theoretical insights, addresses concerns of secondary contamination, and discusses challenges related to selectivity, regeneration, and long-term stability for sustainable remediation.