Engineered Fe-MOG on P-doped Carbon Enables Robust Removal of Microplastics across Water Matrices

Microplastic (MP) pollution has become a serious environmental challenge, considered a contaminant of emerging concern (CEC), require further improvements in existing technologies, creating an urgent demand for efficient and sustainable removal alternatives. In the present work, a novel magnetic composite material anchored on phosphorus-doped carbon (Fe-MOG/PC) was developed using solvothermal decomposition (Fe3O4) and co-precipitation methods for advanced capture of polystyrene microplastics (PS MPs) from various aqueous matrices. Characterization techniques, including XRD, XPS, SEM, and FTIR, confirmed the successful synthesis of the material, revealed the presence of key functional groups and demonstrated the crucial role of Fe2+ /Fe3+ redox pairs in the adsorption process. Batch experiments exhibited that under optimized conditions (adsorbent dose: 50 mg; pH: 7; time: 150 min), the Fe-MOG/PC achieved a high PS removal rate of 96%. The Freundlich isotherm best describes the equilibrium data, indicating that there is multilayer adsorption on the heterogeneous surface, with an adsorption capacity of 105.87 mg/g. The removal mechanism is attributed to the synergistic effects of hydrogen bonds, π-π interactions, and complexation with Fe-O. Importantly, Fe-MOG/PC exhibited excellent performance at different pH ranges, in the presence of common ions, and even in real water (tap water, seawater, and mining water). Overall, this work demonstrates that Fe-MOG/PC is an efficient, sustainable, and operationally flexible adsorbent capable of addressing MPs pollution in various challenging aquatic environments. The finding offers a promising approach for scalable MPs remediation and drives the development of next-generation functional materials for the removal of emerging pollutants. This visual summary serves as the key entry point for the study, providing a concise overview of the study’s core findings and methodology. The graphical abstract illustrates the conversion of Chlorella biomass into phosphorous-doped carbon (PC), followed by the addition of Fe3O4 nanoparticles and H3BTC as a linker to form a magnetic Fe-MOG/PC composite material. The graphic further illustrates the application of Fe-MOG/PC deployment for adsorbing PS MPs in challenging aqueous matrices, demonstrating its practical relevance. The high-performance section quantitatively validates the composite’s superiority through a comparative bar graph, revealing an excellent removal efficiency across all tested environments, a significant enhancement over pristine PC and Fe-MOG, and is supported by the synergistic mechanism of hydrogen bonds, π-π interactions, and Fe-O complexation. In conclusion, the Fe-MOG/PC composite material demonstrated excellent microplastic removal performance, validating its efficiency, sustainability, and flexibility across diverse environments. These findings have established a promising and scalable strategy for MPs remediation and paved the way for the development of next-generation, biomass-derived functional materials to combat emerging pollutants. The Chlorella biomass converted into functionalized P-doped carbon. Magnetic Fe-MOG anchored on the P-doped carbon for MPs remediation. Fe-MOG/PC exhibited excellent performance for PS MPs removal. MPs’ removal efficiency was evaluated in different water matrices.