Removal of Malachite Green Dye from Water Using MXene (Ti3C2) Nanosheets

Abstract

In the present study, new emerging 2D Mxene nanosheets (MXNSs) were synthesized from MAX phase powders of Ti3AlC2 and then characterized using a scanning electron microscope (SEM) and X-ray diffraction (XRD) to explore the chemical and physical properties of the prepared MXNS. The characterization of the synthesized MXNS indicated the formation of exfoliated 2D MXene nanosheets (Ti3C2) as a result of the HF treatment of the MAX phase, which was confirmed by XRD measurements, as the characteristic peaks of 2D MXene nanosheets were only observed. The synthesized MXNS was then used as a solid adsorbent for removing malachite green dye (MG) from water. The effects of different operational factors such as MXNS dose, solution temperature, time, MG concentration, solution pH, and ionic strength have also been evaluated. The adsorption results showed that the temperature of the solution, as well as its pH, significantly influenced MG removal when using MXNS. The optimum removal was obtained within 150 min, with 20 mg of MXNS at ambient temperature and a pH value of 6.0. The maximum removal capacity obtained was 4.6 mg MG per g of MXNS using 5 mg of MXNS with a removal efficacy of 46.0%, and the minimum removal capacity obtained was 2.5 mg MG per g of MXNS using 20 mg of MXNS with a removal efficacy of 99.1%. Finally, the results displayed that the MXNS solid adsorbent was able to absorb a high percentage of MG and maintained reasonable efficiency for four consecutive cycles, indicating that MXNS could be a promising adsorbent in wastewater remediation and environmental sustainability.