Decomposition of 2-naphthol in water and antiviral activity by CoO_x modified (Ce_0.8,Bi_0.2)O_2−δ and (Ce_0.8,La_0.2)O_2−δ in the dark or under visible light

Abstract

Using hydrothermal processing, we prepared a cerium bismuth solid solution oxide ((Ce_0.8,Bi_0.2)O_2−δ, CBO) and a cerium lanthanum solid solution oxide ((Ce_0.8,La_0.2)O_2−δ, CLO). The resultant powders possessed fluorite-type crystal structure. They also decomposed 2-naphthol in water in the dark. From their valence change and temperature dependence, we infer that the Mars–van Krevelen (MvK) mechanism of Ce contributes to this decomposition activity. These materials showed higher decomposition activity under visible light. Modification of CoO_x onto these materials enabled an apparent bandgap decrease and the MvK mechanism of Ce and Co, which led to higher decomposition activity in the dark and under visible light. The CBO activity was higher than that of CLO on the decomposition of 2-naphthol in water, but the CLO antiviral activity was higher than that of CBO. Results suggest that the CLO antiviral activity results from virus deactivation by direct contact with the powder surface.