To effectively remove p-Cresol from blood, adsorbents with high adsorption efficiency needs to be designed and developed. Due to their unique textual properties, wide surface area, and chemical stability, metal-organic frameworks (MOFs), have attracted attention as promising materials for a variety of applications. However, their potential in adsorption processes, especially for removing uremic toxins like p-cresol during dialysis, remains underexplored.

Zeolitic imidazolate frameworks-8 (ZIF-8) and its amine-functionalized derivative (A-ZIF-8) were synthesized in this study with the aim to evaluate its performance as p-Cresol adsorbents in aqueous solutions. To confirm the structural properties and successful amine modification of A-ZIF-8, various characterization techniques were used, such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Brunauer-Emmett-Teller (BET) analysis.

The results revealed that A-ZIF-8 exhibited enhanced crystallinity, surface area, and pore volume compared to pristine ZIF-8. Zeta potential measurements showed a shift from -3.47 mV for ZIF-8 to +35 mV for A-ZIF-8, significantly improving its adsorption capacity of the negatively charged p-cresol. Adsorption studies demonstrated that A-ZIF-8 achieved a maximum p-cresol uptake of 432 mg/g, substantially outperforming ZIF-8’s 289 mg/g. Thermogravimetric analysis and adsorption-desorption isotherms further indicated enhanced thermal stability and microporosity in A-ZIF-8. These findings underscore the effectiveness of amine modification in boosting the adsorption capabilities of ZIF-8, positioning A-ZIF-8 as a superior candidate for uremic toxin removal in protein adsorption.