The Adsorption Performance of MoS2 Nano-rod by Combined with Graphene Oxide for Cr(VI) Removal from Aqueous Solution

Abstract

The rod-like nano-MoS₂/graphene oxide (GO) nanocomposite was fabricated by a facile hydrothermal method, which was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and N₂ adsorption–desorption isotherms, respectively. It was used as adsorbent to remove heavy metal contaminate, such as Cr(VI), from aqueous solution. The investigations on adsorption kinetics and isotherms showed that the pseudo-second-order kinetic and Langmuir isotherm model could well fit the experimental data. The adsorption rate was controlled by both exterior and interior surface diffusion steps. Further investigations on the activation energy and thermodynamics of the adsorption process elucidated that the Cr(VI) adsorption on MoS₂/GO was an endothermic and spontaneous chemi-sorption process. The maximum adsorption capacity was 43.95 mg·g^-1 and the adsorption efficiency of Cr(VI) was enhanced significantly with the coexistence of organic contamination. After recycling five times, the decline of adsorption capacity of MoS₂/GO wasno more than 8.0 %, which indicated that the adsorbents could be reused in Cr(VI) removal practically. The MoS₂/GO nanocomposite has been proved to be a low-cost, efficient and promising adsorbent used for heavy metal ions removal from wastewater.