Inactivation of SARS-CoV-2 and photocatalytic degradation by TiO2 photocatalyst coatings

Abstract

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causative agent of the COVID-19, which is a global pandemic, has infected more than 552 million people, and killed more than 6.3 million people. SARS-CoV-2 can be transmitted through airborne route in addition to direct contact and droplet modes, the development of disinfectants that can be applied in working spaces without evacuating people is urgently needed. TiO2 is well known with some features of the purification, antibacterial/sterilization, making it could be developed disinfectants that can be applied in working spaces without evacuating people. Facing the severe epidemic, we expect to fully expand the application of our proposed effective approach of mechanical coating technique (MCT), which can be prepared on a large-scale fabrication of an easy-to-use TiO2/Ti photocatalyst coating, with hope to curb the epidemic. The photocatalytic inactivation of SARS-CoV-2 and influenza virus, and the photocatalytic degradation of acetaldehyde (C2H4O) and formaldehyde (CH2O) has been investigated. XRD and SEM results show that anatase TiO2 successfully coats on the surface of Ti coatings, while the crystal structure of anatase TiO2 can be increased during the following oxidation in air. The catalytic activity towards methylene blue of TiO2/Ti coating balls has been significantly enhanced by the followed oxidation in air, showing a very satisfying photocatalytic degradation of C2H4O and CH2O. Notably, the TiO2/Ti photocatalyst coating balls demonstrate a significant antiviral activity, with a decrease rate of virus reached 99.96% for influenza virus and 99.99% for SARS-CoV-2.

Retracted: Evaluating the effects of air disinfectants in decontamination of COVID‐19 aerosols

“…Although the inactivation of SARS‐CoV‐2 in aerosols to control its rapid transmission is crucial everywhere, the effectiveness and toxicity of disinfectants are also of concern. 26 , 27 Therefore, it is necessary to identify safe disinfectants that can be applied in public areas without evacuating people. Given the significance of SARS‐CoV‐2 spreading via aerosols, 8 , 10 , 28 particularly in setting connected to healthcare, hospitals, dental units and aerosol‐creating conditions, 11 it is critical to understand how to prevent it from spreading by disinfecting aerosols.…”

“…As has been mentioned before, the most dominant form of this super spread of SARS‐CoV‐2 is airborne transmission. Although the inactivation of SARS‐CoV‐2 in aerosols to control its rapid transmission is crucial everywhere, the effectiveness and toxicity of disinfectants are also of concern 26,27 . Therefore, it is necessary to identify safe disinfectants that can be applied in public areas without evacuating people.…”

Can photocatalysis help in the fight against COVID-19 pandemic?

“… Photocatalyst Light used for activation Tested microorganisms Efficiency Ref. TiO 2 /Ti photocatalyst coatings formed on Al 2 O 3 balls UV (black light fluorescent lamp) SARS-CoV-2 and influenza virus 99.96% inactivation rate for influenza virus and 99.99% inactivation rate for SARS-Co-V-2 in 120 min [ 31 ] Copper oxide grafted with titania (Cu x O/TiO 2 ) Indoor-light-white fluorescence bulb passed through a UV cutoff filter SARS-CoV-2 Denaturalization of spike proteins and fragmentation of RNAs in the SARS-CoV-2 virus in the dark enhanced by irradiation [ 32 ] WO 3 /Cu LED light (1000 lx) SARS-CoV-2, the WK-521 Complete inactivation in 4 h [ 33 ] TiO 2 nanotubes UV-C illumination HCoV-OC43, as well as SARS-CoV-2 Complete inactivation within 30 s [ 34 ] g-C 3 N 4 -based photocatalysts Visible-light irradiation E. coli and MS2 8-log inactivation during 240 min [ 35 , 36 ] AgNPs@TiO 2 UVA and LED SARS-CoV-2 Light intensity dependent activity; complete inactivation (initial Log PFU/cm 2 = 3.079) at 0.25-mW/cm 2 UV [ 37 ] TiO 2 (P25)–SiO 2 -coated PET Film Fluorescent light SARS-CoV-2 0.2-log reduction after 3 h [ 38 ] UV 2.5-log inactivation after 6.5 g-C 3 N 4 /Ag 2 CrO 4 Visible light (LED) SARS-CoV-2 spike protein 77.5% decomposed within 30 min [ 39 ] Cu x O/TiO 2 Visible li...…”

Implication of nanotechnology to reduce the environmental risks of waste associated with the COVID-19 pandemic

“…From the findings, the photocatalytic reaction induced by TiO 2 nanostructures showed good results in removing SARS-CoV-2 from contaminated water. Recently, Lu et al 71 developed a TiO 2 photocatalyst coating on aluminium oxide (Al 2 O 3 ) balls that may successfully inactivate influenza and SARS-CoV-2 viruses. The coating was discovered to be non-toxic and chemically stable, and it may be applied in working environments without requiring people to evacuate.…”