Carbon sphere@layered double hydroxides filled cellulose nanofibers aerogel for Cr(VI) adsorption from aqueous solution

Carbon sphere@layered double hydroxides filled cellulose nanofibers (ACS@LDHs/CNF) aerogel was successfully synthesized. The removal rate of Cr(VI) using ACS@LDHs/CNFs aerogel at a solid-liquid ratio of 1 g/L was 89.4%, which was higher compared to the removal rate of 65.2% using LDHs alone. The adsorption capacity of ACS@LDHs/CNFs for Cr(VI) was determined to be 44.9 mg/g. The adsorption kinetics followed the pseudo-second-order kinetic equation, and the isotherm data showed good agreement with the Langmuir model. The adsorption mechanism of Cr(VI) onto ACS@LDHs/CNFs aerogel was also investigated. Additionally, the ACS@LDHs/CNFs aerogel demonstrated consistent high adsorption efficiency over 4 consecutive cycles of adsorption-regeneration.