Research Information System
Journal of Coordination Chemistry, vol.75, no.11-14, pp.1581-1595, 2022 (SCI-Expanded)
Water pollution by hexavalent chromium, Cr(VI), poses serious concerns due to its detrimental public health effects. In this work, we report the synthesis, characterization, and sorption properties for Cr(VI) by MoS42- intercalated layered double hydroxide, CoAl-MoS4-LDH (CoAl-MoS4). Our results show that CoAl-MoS4 can effectively remove Cr(VI) ions from acidic, neutral, and basic media. At neutral medium, it exhibits a very strong affinity, Kd ∼ 1.91 × 105 mL/g, toward Cr(VI) ions. Under such conditions, this material can remove over 99% of Cr(VI) from a ∼104 ppb of Cr(VI) contaminated solutions, leaving behind residual concentration below the World Health Organization (WHO) defined limit for drinking water. Moreover, our study shows that CoAl-MoS4 is a highly-competent Cr(VI) adsorbent exhibiting a removal capacity (qm) as high as ∼231 mg/g. The CoAl-MoS4 follows pseudo-second order rate kinetics for the sorption of chromate, and the concentration dependent sorption data can be fitted well with the Langmuir sorption isotherm. Furthermore, CoAl-MoS4 is highly selective to Cr(VI) ions in the presence of various competitive ions in contaminated water systems. All these results suggest that CoAl-MoS4 is a very efficient sorbent for decontamination of hexavalent chromate from wastewater systems.