Novel oral spherical activated carbon with ultrahigh specific surface area for adsorption of endogenous toxins

Oral adsorbents can treat chronic kidney disease by removing endogenous toxins from the gastrointestinal tract. Herein, a novel polystyrene-based spherical activated carbon adsorbent with an ultrahigh specific surface area (2125.18 m2·g−1) and a good particle strength (30 N) was successfully prepared via air-oxidation and steam activation. The spherical activated carbon adsorbent possessing hierarchically porous structure presented high creatinine adsorption capacity (up to 300.37 mg·g−1) and excellent adsorption selectivity for different molecular weight adsorbates. Moreover, the pH variation had little effect upon the adsorption capacity of creatinine on the adsorbents. Finally, the mechanism of creatinine adsorption on spherical activated carbon adsorbents was proposed. Van der Waals force and hydrogen bond were considered the driving forces of adsorption for creatinine.