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

Abstract

, synthesized by a one-step hydrothermal method, was investigated for the removal of toluene and inactivation of bacteriophage X 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 (C 0 = 3.59 g/m 3 ) 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 X 174 suspended in air, achieving approximately 3 log inactivation in 60 min (N 0 = ~10 6 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).

Reactive Air Disinfection Technologies: Principles and Applications in Bioaerosol Removal

“…The aerosol microbial suspensions made of Gram-negative bacteria ( Pseudomonas aeruginosa ), Gram-positive bacteria ( Staphylococcus aureu , methicillin-resistant Staphylococcus aureus , Aspergillus fumigatus ), and fungi ( A. fumigatus ) were injected at a flow rate of 1500 mL·min –1 and 0.3 min residence time into a photoreactor with a honeycomb structure of UVA/TiO 2 and yielded removal rates of 92.0%, 88.0%, 93.0%, and 80.7%, respectively . Besides, visible-light-driven photocatalysis is also reported for air disinfection. , For example, simulated sunlight at the intensity of 100 mW·cm –2 was applied to inactivate all the filtered E. coli cells in the air on nonwoven fabrics coated with bactericidal ZIF-8 (MOFilter) and nitrogen-doped titanium dioxide (N-TiO 2 ). , Figure illustrates the fabrication of the commercial mask N95 with modifications of photocatalysts and the corresponding air disinfection efficiency comparisons . For example, the ZIF-8-loaded nonwoven fabrics (MOFilter) exhibited high photocatalytic activity and disinfection power as indicated by the lowest survival under light exposure (Figure a, b).…”

“…40 Besides, visible-light-driven photocatalysis is also reported for air disinfection. 41,42 For example, simulated sunlight at the intensity of 100 mW•cm −2 was applied to inactivate all the filtered E. coli cells in the air on nonwoven fabrics coated with bactericidal ZIF-8 (MOFilter) and nitrogen-doped titanium dioxide (N-TiO 2 ). 43,44 Figure 2 illustrates the fabrication of the commercial mask N95 with modifications of photocatalysts and the corresponding air disinfection efficiency comparisons.…”

Thermal catalytic device for toluene decomposition via direct heating

“…VOCs are emitted by various solids and liquids in our living and working environments and high concentrations or long-term exposure pose a significant health risk [2]. Methods investigated to reduce VOCs involve adsorption [3][4][5][6], photocatalytic decomposition [7,8], catalytic oxidation [1,2,[9][10][11][12][13][14][15], and non-thermal plasma. A disadvantage of adsorption methods is the necessity for the periodic post-process treatment of spent adsorbents involving the desorption of captured VOCs or regeneration of the adsorbent [16,17].…”