Amino-functionalized Ti-metal-organic framework decorated BiOI sphere for simultaneous elimination of Cr(VI) and tetracycline

A subtle flower-like MIL-125-NH2@BiOI was fabricated by a facile solvothermal method for simultaneously eliminating Cr(VI)/tetracycline mixed pollutants under visible light. The strong interaction between amino in MIL-125-NH2 and Bi3+ of BiOI promotes the formation of this unique inlaid structure and enables the favorable contact between MIL-125-NH2 and BiOI, thus accelerating the transfer of charge carriers. Remarkably, MIL-125-NH2@BiOI displays a superior activity compared with that of two monomers for the photocatalytic reduction of Cr(VI) and degradation of tetracycline. More significantly, the photocatalytic efficiency can be further boosted in the coexistence of Cr(VI) and tetracycline, which is 1.8 and 1.6 times that of single Cr(VI) and tetracycline, respectively. The synergistic effect between Cr(VI) reduction and tetracycline oxidative degradation can further facilitate the separation of photo-induced electrons and holes, resulting in the improved efficiencies in the Cr(VI)/tetracycline coexistent environment. This work sheds light on that MOF-based photocatalysts possess huge potential for practical environmental remediation.