Hydrothermal synthesis of MXene-MoS2 composites for highly efficient removal of pesticides

Ti3C2 is regarded as the most popular MXene, which has been extensively investigated as a candidate for fabrication of adsorbents to remove environmental pollutants. However, the adsorption capacity of unmodified MXene is limited owing to the lack of specific adsorption sites. In this work, we reported a simple hydrothermal method for preparation of Ti3C2-MoS2 composites and examined their adsorption removal of organic pesticide paraquat (PQ) for the first time. The adsorption equilibrium will reach within 30 min and the adsorption capacity was increased from 8.7 mg/g to 105.53 mg/g as compared with that of Ti3C2. The adsorption process is more inclined to follow the Freundlich isotherm model and quasi-second-order kinetic model, which points to that the adsorption process is multilayer adsorption and may followed both physical adsorption and chemical adsorption. Adsorption of PQ on Ti3C2-MoS2 is a spontaneous exothermic process and many factors, such as temperature, pH values, and ion strength can influence the adsorption performance. The obvious increase of adsorption performance of Ti3C2-MoS2 might be ascribed to the increase of specific surface area after the introduction of flower-like MoS2. More than that, PQ also might be catalytically degraded by Ti3C2-MoS2 for its semiconductor property.