Effect of Flower‐Like and Spherical Nanostructured MoS₂ on the Adsorption Properties of Cr(VI) Ions

Abstract

MoS2 nanostructures with different morphologies were synthesized using a simple in‐situ hydrothermal process by different surfactants like hexadecyl trimethyl ammonium bromide (CTAB) and polyvinyl pyrrolidone (PVP), and the effect of morphologies on the adsorption property for Cr(VI) were investigated. It can be found that flower‐like and spherical MoS2 nanostructures were synthesized and their morphologies largely effected the adsorption performance toward Cr(VI) ions. Flower‐like MoS2 exhibited the surface area of 41.9 m2 g−1 with fairly high adsorption capacity of 66.1 mg g−1 toward Cr(VI), fitting well to pseudo‐second order kinetic model and Langmuir isotherm model. Moreover, this as‐prepared nanostructured MoS2 also presented satisfying reusability for removal of Cr(VI) and were even suitable for the selective removal of Cr(VI) in the presence of NO3−. It may provide a potential route to enhance the adsorption property of MoS2 toward heavy metal ions through adjusting the morphology of the MoS2 sample, which would expand the applications of MoS2 in the field of treatment of the heavy metal wastewater.

Recent Advances in Two-Dimensional MoS2 Nanosheets for Environmental Application

“…It is reported that 1T MoS 2 exhibited the high adsorption capacity (200.3 mg/g), compared to 2H MoS 2 (70.7 mg/g) and M MoS 2 (82.8 mg/g, Figure A) . Sun et al reported that the maximum sorption capacity of Cr­(VI) on pristine 2D MoS 2 via a facile one-step hydrothermal method was 84.03 mg/g, which was slightly higher than the flowerlike nanostructures MoS 2 through a surfactant-assisted hydrothermal method (66.1 mg/g) . In order to increase the adsorption performance and redox capacity, various MoS 2 -based composites were widely synthesized in recent years.…”

“…210 Sun et al reported that the maximum sorption capacity of Cr(VI) on pristine 2D MoS 2 via a facile one-step hydrothermal method was 84.03 mg/g, 213 which was slightly higher than the flowerlike nanostructures MoS 2 through a surfactant-assisted hydrothermal method (66.1 mg/g). 214 In order to increase the adsorption performance and redox capacity, various MoS 2based composites were widely synthesized in recent years. For instance, Yang et al reported that the maximum sorption capacities of Cr(VI) on MoS 2 @Fe 3 O 4 composites (290.2 mg/g at pH 5.0, T = 298 K, Figure 5B) 208 was significantly higher than those of the other MoS 2 -based composites such as MoS 2 / CTAB (79.4 mg/g), 212 MoS 2 /rGO(80.8 mg/g), 211 LDHs@ MoS 2 (76.3 mg/g at pH 5.0), 215 chitosan-modified/MoS 2 (158 mg/g at pH 5.0).…”