Hydrothermally synthesis of MWCNT/N-TiO2/UiO-66-NH2 ternary composite with enhanced photocatalytic performance for ketoprofen

A novel ternary heterojunction MWCNT/N-TiO2/UiO-66-NH2 was synthesized by in-situ solvothermal-hydrothermal approach, showing superior photocatalytic degradation of KET under visible-light irradiation. The optimal MWCNT/N-TiO2/UiO-66-NH2 (3:7) composite exhibits the highest degradation efficiency of KET (96%) in 120 min in comparison with pristine TiO2, N-TiO2, MWCNT, UiO-66-NH2 and MWCNT/N-TiO2. The improved photocatalytic activity of MWCNT/N-TiO2/UiO-66-NH2 can be ascribed to its improved visible-light absorption range, the large specific surface area based on UiO-66-NH2 as well as the formation of an effective heterojunction. The formed ternary composite facilitates the separation and transfer of photoexcited charge carrier, which is confirmed from the results of PL. The photocatalytic mechanism is further proposed based on the trapping experiment, and the transfer process of photoinduced electron-hole pairs is discussed. This work provides an effective strategy for designing a new ternary photocatalytic system toward degradation of organic pollutants.