Metal-organic frameworks decorated Ti3C2Tx MXene nanosheets (MXene@UiO-66) for enhanced photocatalytic dye degradation

In this study, the zirconium-based metal-organic framework (UiO-66) was in situ grown on the Ti3C2Tx MXene nanosheets for photocatalytic degradation of organic dyes. The microstructure, crystal structure, and photoelectrochemical properties of the MXene@UiO-66 nanocomposite were characterized using multiple characterization techniques such as FESEM, EDX, XRD, FTIR, etc. The incorporation of MOF into MXene nanosheets considerably enhanced the photocatalytic activity of the MXene@UiO-66 heterostructure in the degradation of methylene blue (MB) and direct red 31 (DR31) dyes. The MB and DR31 degradation efficiency of 78 % and 56%, respectively, within 60 min of UV-visible irradiation were achieved. The stability and reusability of the MXene@UiO-66 composite were also studied and found that the degradation rate of the heterojunction photocatalyst remained at 74% and 50.6%, for MB and DR31, respectively, even after four successive cycles. Furthermore, the photocatalysis mechanism of the MXene@UiO-66 nanocomposite was also studied by radical quenching experiments, indicating the crucial role of the hole. The enhanced photocatalytic dye degradation of MXene@UiO-66 nanocomposite was attributed to the heterostructures between Zr-MOF and Ti3C2Tx MXene, which facilitate the transfer of photo-generated carriers by shortening the charge transfer path. The current work provides new insights into the design and fabrication of next-generation photocatalysts for the degradation of organic pollutants from aqueous solutions.