Hierarchical CoTiO₃ microrods on Ti₃C₂T_x MXene heterostructure as an efficient sonocatalyst for bisphenol A degradation

One-dimensional CoTiO₃ microrods decorated on two-dimensional layered MXene nanosheets (CoT@MX) were synthesized via a facile liquid self-assembly method for use in bisphenol A (BPA) degradation. Different characterization techniques were adopted to investigate their structure, chemical state, morphology, and optical properties. The results revealed that the CoT@MX heterostructure was successfully fabricated with strong interface contact and an intimate interaction between CoTiO₃ and MXene, which significantly boosted the sonocatalytic activity compared to that of sole CoTiO₃ and MXene. In particular, the CoT@MX (1:0.5) nanocomposite displayed an excellent sonocatalytic performance, and its removal efficiency for BPA was 96.9% within 90 min. The influence of various reaction factors, including the catalyst dosage, initial concentration of BPA, operational pH, ultrasonic power, water matrix, and effects of coexisting ions, during BPA degradation was investigated systemically. The MXene nanosheets could provide new surface-active sites, which were conducive to the interaction between the catalyst and BPA pollutant molecules. Furthermore, the quenching tests and electron spin resonance analysis revealed that ^[rad]OH and O₂^[rad]− jointly contributed to BPA degradation. Finally, the feasible sonocatalytic reaction mechanism of CoT@MX was elucidated.