Ti3C2-MXene quantum dot/Fe-MOF heterostructure with enhanced visible-light photocatalytic performance

The development of efficient photocatalysts for water purification is vital to mitigate the global clean water shortage. In this study, a heterostructured photocatalyst was synthesized by incorporating Ti3C2-MXene Quantum Dots (MQDs) into an iron-based metal-organic framework (NH2-MIL-88B(Fe) MOF) to enhance photocatalytic activity. The prepared composites were systematically characterized by XRD, FTIR, TEM, FE-SEM, UV–Vis DRS, BET, XPS, and PL analyses. Compared with the pristine MOF, the results revealed markedly enhanced visible-light absorption and significantly reduced charge-carrier recombination, confirming the successful integration of MQDs into the MOF heterostructure. The degradation of methylene blue (MB) under visible light irradiation was used to assess the photocatalytic performance. While the pristine MOF showed high adsorption (73.01%) but negligible photocatalytic activity, and bare MQDs exhibited only 23.33% degradation, the 50MQDs/MOF composite achieved a remarkable photocatalytic efficiency of 62.97%. This represents a multiplicative enhancement and underscores the critical role of the heterostructure in unlocking the inherent photocatalytic potential of the MOF. Radical scavenging experiments confirmed that electrons (e−) and superoxide radicals () are the dominant reactive species in the degradation process. The enhanced activity was attributed to the synergistic interaction between MOF and MQDs, resulting in superior adsorption capacity, more efficient charge separation, and improved electron transfer. These findings indicate that MQD/MOF heterostructures hold strong promise as sustainable photocatalysts for real-world wastewater treatment involving organic pollutants.