Structure-tuned Ti₃C₂T _x MXene for efficient adsorption and visible-light-assisted removal of dye and pharmaceutical...

Finding effective materials for the removal of pollutants from wastewater has become an essential requirement in environmental protection and the development of advanced water-treatment technologies. In this study, Ti₃C₂T _x -MXene was synthesized using two methods (i.e., sol-gel and hydrothermal). The influence of synthesis parameters, including etching agent (i.e., LiF and NaF), temperature (i.e. 38, 80 and 90 °C), and reaction time (i.e., 3 and 7 days), on the structural characteristics and pollutant-removal performance of MXene was systematically investigated. The synthesized samples were evaluated for the removal of dye and pharmaceutical contaminants, including methylene blue (MB), tetracycline (TC), carbamazepine (CBZ), and phenazopyridine (PhP). The results revealed that the sample synthesized using LiF (i.e., LTi2) as an etchant at 90 °C possessed the highest specific surface area and exhibited higher adsorption efficiency compared to other samples. At an initial concentration of 10 ppm, LTi2 removed more than 93% of MB and 88% of PhP within 60 min through adsorption. At a concentration of 40 ppm, adsorption efficiencies of approximately 48%, 29%, and 18% were obtained for MB, TC, and CBZ, respectively. Under subsequent visible-light irradiation, further pollutant removal was observed, resulting in total removal efficiencies exceeding 98% for MB and 93% for PhP at 10 ppm, while overall removal efficiencies of 59%, 64%, and 37% were achieved for MB, TC, and CBZ, respectively, at 40 ppm. These findings demonstrated that careful control of the synthesis conditions was an effective strategy for tailoring the MXene structure and improving its adsorption-dominated and visible light assisted pollutant removal performance.