Tuning the high-energy state of Fe-GLC via high salinity stacking effect for ECs spontaneous destruction in waters

Achieving cost-effective removal of organic contaminants in saline wastewater remains a persistent global challenge. Current advanced oxidation processes based on reactive oxygen species suffer from unsatisfactory efficiency and substantial energy demands. Herein, we synthesized a Fe coordinated chlorapatite (CAP)-doped graphene-like structure catalyst (Fe-GLC) with cation-π interactions. Fe-GLC exhibited high efficiency and stability for various emerging contaminants (ECs) degradation without additional energy input, and even achieved 100% removal for BPA in municipal wastewater and high-salinity pesticide wastewater (3.5%). The reaction rate was increased by 1.14 to 1.81 fold with 100 mM∼400 mM salinity. The stacking effect of salinity on GLC π system effectively induced surface charge rearrangement and stronger electric field, thus opening the charge transfer channels of ECs → GLC → Fe species and forming more high-spin Fe species and highly compressed GLC π system. This significantly increased electric field energy and weakened the bond energy of ECs, thereby initiating spontaneous surface destruction of ECs under the action of O₂ as the electron acceptor. Our findings highlight the potential of utilizing salinity-mediated surface multicomponent synergistic coordination to regulate the high-energy state of catalysts, offering a promising avenue for developing sustainable and cost-effective novel technologies for ECs purification in high-salinity wastewater.