MX@MIL-125(Ti)-mediated sonocatalytic degradation for the dyes and microplastics

Abstract

Organic pollution has attracted global attention for the threat to the biota. In this study, the catalyst-mediated sono-degradation was purposefully employed to remove the organic pollutants including dyes and microplastics (MPs) because it could provide a green and sustainable strategy in industrial production. Herein, the Ti-based MOFs (Ti-MOFs) was successfully prepared on the Ti3C2 MXene by the hydrothermal method, forming new plicated MX@MIL-125(Ti). The as-prepared composite had lower specific surface area than the MIL-125(Ti), but it remained porous structure, and the presence of O-Ti-O species and graphitic carbon could help to enhance the photosensitive and catalytic activity. Significantly, the MX@MIL-125(Ti) showed good catalytic removal performances under ultrasound irradiation, and could clear away over 90 % Rhodamine B (RhB) within 60 min or over 75.0 % micro-polyethylene (micro-PE) within 4 h, where the removal process obeyed the pseudo first-order kinetic reaction model and the sonocatalytic degradation was superior to the adsorption. Moreover, a degradation-dominant mechanism was proposed to administrate the MX@MIL-125(Ti)/ultrasound treatment of organic molecules. Thus, the sonocatalysis of Ti-MOFs will be attractive to apply in the degradation of organic contaminants.