ZnO/Mo2TiC2 MXene nanohybrids for enhanced solar-driven photocatalytic degradation of tetracycline and organic pollutants in contaminated water

This study presents, for the first time, the photocatalytic degradation of tetracycline antibiotics using Mo 2 TiC 2 MXene-integrated ZnO nanohybrids. Considering the persistence and adverse environmental and health impacts of tetracycline contamination in water bodies, the development of efficient photocatalysts for its removal is of critical importance. ZnO/MXene nanohybrids were synthesized via a hydrothermal-assisted sol-gel method, wherein Mo 2 TiC 2 MXene was derived from its MAX (Mo 2 TiAlC 2 ) phase through HF etching. Comprehensive physicochemical characterizations were conducted to elucidate the material properties and interfacial interactions. TEM analysis confirmed the intimate coupling between ZnO and MXene layers, while XRD and Raman spectroscopy verified the successful integration of MXene within the ZnO matrix. Among the different compositions prepared, the ZnO/MXene nanohybrid containing 5 ​wt% MXene (ZMX-5) demonstrated the highest photocatalytic activity, achieving 93 ​% tetracycline degradation in 120 ​min, corresponding to a rate constant ( k ) of 24.7 ​× ​10 −3 min −1 , which is approximately 8.5 times higher than the pristine ZnO. To validate its broader applicability, the material was also tested for the degradation of methylene blue (MB), achieving 72 ​% degradation within 180 ​min and a rate constant of 12.93 ​× ​10 −3 min −1 . The enhanced photocatalytic performance of ZMX-5 is primarily attributed to improved charge carrier separation and suppressed electron-hole recombination, as confirmed by photoluminescence analysis. XPS results indicated strong chemical bonding between ZnO and Mo 2 TiC 2 MXene, while electrochemical impedance spectroscopy (EIS) Nyquist plots revealed superior charge transfer characteristics in the hybrid. These results highlight the promise of ZnO/MXene heterostructures as efficient photocatalysts for the degradation of antibiotics and dye contaminants in wastewater treatment applications.