Efficient elimination of Cr(VI) from aqueous solutions using sodium dodecyl sulfate intercalated molybdenum disulfide

In recent years, the heavy metal ions have been immoderately released into the ecological system and result in potential hazardous to public health. Herein, the sodium dodecyl sulfate intercalated molybdenum disulfide (SDS-MoS₂) was synthesized for the adsorption of Cr(VI). The SDS molecule was flat and vertically intercalated into the interlayer of MoS₂, which was further evidenced by density functional theory calculations. The capture of Cr(VI) on the sphere-like SDS-MoS₂ relied on solution pH. The retention of Cr(VI) on SDS-MoS₂ attained 63.92 mg/g, and the removal process was endothermic, spontaneous and increased with temperature increasing. The main removal mechanism of Cr(VI) onto SDS-MoS₂ was Cr(VI) fixing on the surface of the composites by chemisorption involving possible Cr-S coordination bonding. More importantly, Cr(VI) passed into the increased interlamination and reacted at the interlamination of SDS-MoS₂, which was further proved at molecular level. The results can provide critical information for the application of SDS-MoS₂ in Cr(VI) elimination or other kinds of pollutants removal in natural aquatic environment.