Enhanced degradation of tetracycline by TiO2@MXene with peroxydisulfate under visible light irradiation

Abstract

Photocatalysis and peroxydisulfate (PS) based advanced oxidation techniques are promising technologies in the field of water treatment that can be used to destroy increasingly persistent organic contaminants. The current work used a simple hydrothermal approach to synthesize a catalyst made of composites of TiO2 nanospheres and multi-layer Ti3C2Tx sheets (TiO2@MXene). Tetracycline (TC) was then effectively degraded by the TiO2@MXene material integrated with PS activation (300 mg/L). Under simulated sunlight (AM 1.5G, P = 2.8 W) irradiation, the combination method dramatically increases TC degradation. Following a 30-min treatment with 300 mg/L TiO2@MXene (wt.10 %), the optimal efficiency can reach 100 %. As the reactive functional species, holes (h+), SO4-•, •OH, and •O2− dominate the catalytic process. Furthermore, investigation was conducted into significant factors such as catalyst dosage, PS dosage, common anions, and TiO2 loading dosage. The TiO2@MXene material was demonstrated to be a feasible and sustainable strategy worth taking into consideration in the mitigation of emerging water contaminants due to its ease of recovery, stability of surface properties, and recyclability. Furthermore, the proposed degradation mechanism further demonstrated the viability of TiO2@MXene with PS in TC degradation. This, this study provides insights into the design of effective photocatalyst coupling PS activation for the efficient degradation of organic pollutants.