Visible-light photocatalysis over MIL-53(Fe) for VOC removal and viral inactivation in air

Abstract

MIL-53(Fe), synthesized by a one-step hydrothermal method, was investigated for the removal of toluene and inactivation of bacteriophage ⲪX 174 in air under visible light illumination. MIL-53(Fe) exhibited superior photochemical activity to other metal organic frameworks synthesized by the same method with different metal precursors. Analytical methods of diffuse reflectance spectroscopy, BET specific surface area analysis, SEM-EDS, FT-IR analysis, XRD, Mott-Schottky analysis, and XPS were used to characterize MIL-53(Fe). The illuminated MIL-53(Fe) removed input toluene (C0 = 3.59 g/m3) by 66% in 6 h by adsorption and subsequent photocatalytic oxidation. High humidity and temperature, and the anoxic condition inhibited the toluene removal. MIL-53(Fe) showed sustainable toluene removal for five consecutive runs, even though the photocatalytic activity slightly decreased. Meanwhile, the illuminated MIL-53(Fe) also resulted in the inactivation of ⲪX 174 suspended in air, achieving approximately 3 log inactivation in 60 min (N0 = ~106 PFU/mL air). Similar to toluene removal, the presence of oxygen and low humidity were beneficial for viral inactivation. The photo-generated holes are believed to be responsible for the organic degradation and viral inactivation by the illuminated MIL-53(Fe).