MOF-808/graphene oxide composite as an efficient adsorbent for urea removal: experimental and atomistic study

This study explores the synthesis and evaluation of a novel composite material based on the in-situ growth of Metal-Organic Framework (MOF) on graphene oxide composite for the removal of urea from aqueous environments, particularly for artificial kidney applications. The synthesized MOF-808@rGO composite exhibits enhanced stability, tailored surface properties, and tunable pore structures, enabling effective urea adsorption. Both experimental methods and atomistic simulations were employed to investigate the interaction mechanisms between urea molecules and the composite. The synthesis process involves the in-situ growth of MOF-808 on GO surfaces, followed by heat treatment to produce the MOF-808@rGO composite. The resulting material was characterized using BET, SEM, PXRD, and FTIR analyses. Performance results indicate that the composite can achieve up to 755 mg/g of urea adsorption at a concentration of 2000 ppm, showing excellent recyclability over multiple adsorption cycles. The results demonstrate a significant improvement in urea adsorption capacity compared to the individual components. This enhancement is attributed to the synergistic effects of MOF-808 porosity and the presence of graphene oxide, which improve MOF dispersion, interfacial charge distribution, and the accessibility of adsorption sites. In-situ growth of MOF-808 on graphene oxide enhances pore accessibility and modifies interfacial surface chemistry, leading to increased urea-adsorbent interactions and improved structural stability of the composite. Notably, the synthesized composite maintained structural integrity and demonstrated reusability, addressing challenges related to the regeneration of adsorbents in clinical settings. The performance metrics were evaluated under simulated dialysis conditions, revealing promising outcomes for integrating these materials into portable dialysis systems. The findings contribute valuable insights to the optimization of MOF-graphene composites, paving the way for next-generation solutions in kidney disease management. This work underscores the potential of the MOF-808/graphene oxide composite as an innovative approach to enhance urea removal efficiency, ultimately benefiting patients with compromised renal function and improving the efficacy of dialysis technologies.