Strong adsorption and high stability of the thin-layered MXene adsorbent: Simple synthesis and application to reduce the toxicity of wastewater towards mung beans

Abstract

The thin-layered MXene was prepared by etching Ti3AlC2 with HCl/LiF solution using ultrasonic-assisted peeling and gradient centrifugation. The characterization by TEM, AFM and FT-IR, BET showed that the thin-layered MXene had larger specific surface area and more developed pore structure, and also possessed more oxygen-containing functional groups, which improved the adsorption performance on Rhodamine B (RhB). The maximum adsorption of RhB could reach 167.82 mg g−1 at room temperature and neutral conditions. The adsorption process fitted well with the pseudo-first-order kinetic model and pseudo-second-order kinetic model, and the adsorption isotherms matched with the Langmuir adsorption isotherm model. This indicated that the adsorption was the result of both physical and chemical adsorption, and the adsorption was monolayer adsorption. Finally, the ecotoxicological effects of organic dye RhB on crops were explored. The treated wastewater could promote the growth of mung bean, indicating that the toxicity of the wastewater after adsorption treatment was significantly reduced.