Performant removal of creatinine using few-layer-graphene/alginate beads as a kidney filter

Reduction of renal function, such as creatinine adsorption is one of the most common and dangerous diseases. Dedicated to this issue, developing high-performance, sustainable, and bio-compatible adsorbing materials is still challenging. Herein, barium alginate (BA) and BA containing few-layer graphene (FLG/BA) beads were synthesized in water from sodium alginate, also acting as bio-surfactant in in-situ exfoliation of graphite to FLG. The physicochemical characteristics of the beads demonstrated an excess of barium chloride used as a cross-linker. The efficiency and sorption capacity (Q_e) of creatinine removal increase with processing duration reaching 82.1, 99.5 %, and 68.4, 82.9 mg·g^-1 for BA and FLG/BA, respectively. The thermodynamic parameters detect the enthalpy change (ΔH°) of about -24.29 and -36.11 kJ·mol^-1 and the entropy change (ΔS°) of around -69.24 and -79.46 J·mol^-1 K^-1 for BA and FLG/BA, respectively. During the reusability test, the removal efficiency decreases from the optimal first cycle to 69.1 and to 88.3 % in the sixth cycle for BA and FLG/BA, revealing superior stability of FLG/BA. The MD calculations confirm a higher adsorption capacity of FLG/BA composite compared to BA alone, clearly confirming a strong structure-property relation.