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In this work,a facile method was adopted to synthesize molybdenum disulfide/reduced graphene oxide(MoS_2/rGO) composites through an L-cysteine-assisted hydrothermal technique.The as-prepared MoS_2/rGO composites were firstly applied as adsorbents for efficient elimination of Pb(Ⅱ) ions.Batch adsorption experiments showed that the adsorption of Pb(Ⅱ) on MoS_2/rGO followed pseudo-second-order kinetic model well.The adsorption of Pb(Ⅱ) was intensely pH-dependent,ionic strength-dependent at pH < 9.0 and ionic strength-independent at pH > 9.0.The presence of humic acid(HA) enhanced Pb(Ⅱ)adsorption obviously.The MoS_2/rGO composites exhibited excellent adsorption capacity of384.16 mg g ~1 at pH 5.0 and T= 298.15 K,which was superior to MoS_2(279.93 mg g ~1) and many other adsorbents.The thermodynamic parameters suggested that the adsorption process of Pb(Ⅱ) on MoS_2/rGO composites was spontaneous(AG~θ < 0) and endothermic(AH~θ > 0).The interaction of Pb(Ⅱ) and MoS_2/rGO was mainly dominated by electrostatic attraction and surface complexation between Pb(Ⅱ) and oxygen-containing functional groups of MoS_2/rGO.This work highlighted the application of MoS_2/rGO as novel and promising materials in the efficient elimination of Pb(Ⅱ) from contaminated water and industrial effluents in environmental pollution management.
In this work, a facile method was adopted to synthesize molybdenum disulfide / reduced graphene oxide (MoS_2 / rGO) composites through an L-cysteine-assisted hydrothermal technique. The as-prepared MoS_2 / rGO composites were firstly applied as adsorbents for efficient elimination of Pb (Ⅱ) ions. Baptism experiments showed that the adsorption of Pb (Ⅱ) on MoS_2 / rGO was pseudo-second-order kinetic model well. The adsorption of Pb (Ⅱ) was intensely pH-dependent, pH = 9.0 and ionic strength-independent at pH> 9.0. The presence of humic acid (HA) enhanced Pb (Ⅱ) adsorption obviously. The MoS_2 / rGO composites exhibited excellent adsorption capacity of 384.16 mg g ~ 1 at pH 5.0 and T = 298.15 K, which was superior to MoS 2 (279.93 mg g ~ 1) and many other adsorbents. The thermodynamic parameters suggested that the adsorption process of Pb (II) on MoS_2 / rGO composites was spontaneous (AG ~ θ <0) and endothermic (AH ~ θ> 0) .The interaction of Pb (Ⅱ) and MoS_2 / rGO was mai nly dominated by electrostatic attraction and surface complex between Pb (II) and oxygen-containing functional groups of MoS_2 / rGO.This work highlighted the application of MoS_2 / rGO as novel and promising materials in the efficient elimination of Pb (II) from contaminated water and industrial effluents in environmental pollution management.