Vanadium as a Ti-like mediator boosting electronic transmission in Fe-based MOFs for photocatalytic sterilization

Abstract Efficient metal–organic frameworks (MOFs) photocatalytic bactericidal catalysts are urgently needed in water purification. Herein, a Fe-MOF (MIL-88B-NH 2 (V 1 Fe 5 ) with promoted electron transport was achieved by vanadium (V) ions doping and V/Fe ratio optimization, showing excellent photocatalytic bactericidal activity against E. coli under visible light irradiation (99.92%). The efficient antibacterial mechanism, V as a Ti-like mediator boosting electronic transmission in MIL-88B-NH 2 (V 1 Fe 5 ), was revealed by its band structure, transient photocurrent, electrochemical impedance spectroscopy, and scavenger quenching experiments. The enhancement of photocatalytic bactericidal performance of Fe-MOFs by V–ion-doping was confirmed by two other Fe-MOFs, MIL-53-NH 2 (V 1 Fe 5 ) and MIL-101-NH 2 (V 1 Fe 5 ), with the same metal ions and ligands, both of which have higher performance than the corresponding undoped MOFs. Among them, MIL-88B-NH 2 (V 1 Fe 5 ) exhibits the highest photocatalytic bactericidal activity due to its suitable metal clusters ([M( μ 3 -O)] cluster) and topological structure (three-dimensional rhomboid network structure). This work demonstrated the amplification effect of V ion doping on electron transport in Fe-MOFs photocatalysts.