Adsorption performance and mechanism of MoS2/BC composite for U(VI) from aqueous solution

A molybdenum disulfide/biochar (MoS 2 /BC) composite was synthesised by a facile hydrothermal process and used for the adsorption of U(VI) from aqueous solution through batch experiments. Results showed that MoS 2 /BC exhibit a saturated adsorption capacity of 451.3 mg/g at pH = 5, t  = 60 min, T  = 298 K, M/V  = 0.02 g/L, C U(VI)  = 10 mg/L, which was higher than that of MoS 2 and biochar. The process of MoS 2 /BC for U(VI) adsorption was better simulated via the pseudo-second-order kinetic model ( R 2  = 0.999) and Langmuir isotherm model ( R 2  = 0.999). The adsorption mechanism of U(VI) includes chemical adsorption, electrostatic attraction, surface complexation of oxygen-containing functional groups, cation- π bond and coordination of S group. After five adsorption–desorption experiments, the elimination rate remained above 80%.