Cellulose nanocrystal-infused polymer hydrogel imbued with ferric-manganese oxide nanoparticles for efficient antinomy removal

Antimony is a highly poisonous pollutant that needs to be removed from water to ensured safety. In this work, we have fabricated a novel adsorbent, the ferric-manganese oxide (FeMnO_x) nanoparticles embedded cellulose nanocrystal-based polymer hydrogel (FeMnO_x @CNC-g-PAA/qP4VP, denoted as FMO@CPqP), specifically engineered for the remediation of antimony-laden water. Comprehensive evaluations have been conducted to investigate the efficacy of the FMO@CPqP hydrogel in removal of antimony from water. The hydrogel exhibits superior affinity for antimony, with maximum adsorption capacities of 276.1 mg/g for Sb(III) and 286.8 mg/g for Sb(V). The adsorptive dynamics, governed by the kinetics and isotherm analyses, elucidate that the immobilization of both Sb(III) and Sb(V) is facilitated through a homogeneous and monolayer chemisorption mechanism. The hydrogel has a three-dimensional interconnected porous structure and exhibits good swelling behavior, which facilitates the rapid absorption of antimony ions by this high surface area hydrogel into the channels. Furthermore, various effects, including the oxidation and inner-sphere coordination mediated by FeMnO_x NPs and the electrostatic attractions of the quaternized P4VP chains, promote the immobilization of antimony species. Owing to its high removal efficiency, stability and reusability, the FMO@CPqP hydrogel emerges as an exemplary candidate for the removal of antimony contaminants in water treatment processes.