supported by Science Challenge Project (JCKY2016212A04)； the National Natural Science Fondation of China(91326202,21577032,and 21403064)； the Fundamental Research Funds for the Central Universities(JB2015001)； the National Special Water Programs(2015ZX07203-011,2015ZX07204-007)；
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 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 (?G~θ < 0) and endothermic (?H~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.