The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has spread worldwide and placed countries in emerging, rapidly transforming situations. More than 88 million cases of COVID-19 and 1,926,625 deaths are reported to WHO as of 11 January 2021 (WHO, 2021) . The SARS-CoV-2 has been detected in specimens from the respiratory tract, nasopharyngeal sites, and feces in COVID-19 patients (Wang et al., 2020) . The viral transmissions can occur via close human-to-human contact or via contacting a contaminated surface. To reduce the risks of environmental contamination, a myriad of disinfectants/ sanitizing agents/biocidal agents are available, but their effectiveness is likely to depend on many factors such as the concentration of the agent, the reaction time, temperature, and the organic load (Lin et al., 2020) .Although the effectiveness of representative sanitizers such as ethanol and sodium hypochlorite in deactivating SARS-CoV-2 has been studied (Aboubakr et al., , Lin et al., 2020, Takeda et al., 2020 , this information is limited to a few liquid disinfectants and does not obtain a comprehensive picture about the effects of solid materials on SARS-CoV-2. Photocatalysts are sustainable, environmental friendly and potent disinfectants that generate free radicals (i.e. superoxide and hydroxyl radicals) when excited by light strikes. Thus, they are efficient biocides against many pathogens including bacteria, viruses and fungi (Habibi-Yangjeh et al., 2020, Yemmireddy et al., 2017 , but, to our knowledge, their effects on SARS-CoV-2 have not been investigated. In this study, we examined the virucidal activity of a tungsten trioxide (WO3) -based visible light-responsive photocatalyst, RENECAT TM against SARS-CoV-2 under visible light irradiation. To ＊

There is a worldwide attempt to develop prevention strategies against SARS-CoV-2 transmission. Here we examined the effectiveness of visible light-responsive photocatalyst RENECAT on the inactivation of SARS-CoV-2 under different temperatures and exposure durations. The viral activation on the photocatalyst-coated glass slides decreased from 5.93∓0.38 logTCID50/ml to 3.05∓ 0.25 logTCID50/ml after exposure to visible light irradiation for 6h at 20 degree C. On the other hand, lighting without the photocatalyst, or the photocatalyst-coat without lighting retained viral stability. Immunoblotting and electron microscopic analyses showed the reduced amounts of spike protein on the viral surface after the photocatalyst treatment. Our data suggest a possible implication of the photocatalyst on the decontamination of the SARS-CoV-2 in indoor environments, thereby preventing indirect viral spread.