Highly efficient scavenging of uranium(VI) by molybdenum disulfide loaded ferrous sulfide composites: Kinetics, thermodynamics and mechanism aspects

Background This work aims at developing a nanocomposite in which ferrous sulfide nanoparticles are loaded onto molybdenum disulfide (MoS 2 @FeS) for the removal of U(VI) from an aqueous solution. Methods The removal process was carried out by batch experiment. Characterizations of MoS 2 and MoS 2 @FeS before and after reaction have been studied by SEM-EDS, TEM, FTIR, XRD, XPS, and BET analysis. Significant findings Reductive conversion of U(VI) to U(IV) was the primary reaction mechanism, where S(-Ⅱ) is the predominant reductant. At the same time, the functional groups of -S, Fe-O, and Fe-OH can adsorb different U(Ⅵ) species. Moreover, the effects of pH, adsorbent dosage, initial concentration, reaction time, and temperature on removal were discussed and compared by batch experiments, and the outcomes show that the U(VI) removal quantity of MoS 2 @FeS is generally higher than MoS 2 at the same condition. Finally, different kinetic models, isotherm models, and thermodynamic parameters are introduced to further explore the adsorption process and types of MoS 2 and MoS 2 @FeS under various pH and temperatures, which demonstrate that the two materials fit well with the pseudo-second-order model and Freundlich model. This work provides a new idea that MoS 2 @FeS nanocomposite has high superiority and prospects for the effective decontamination of U(VI).