Photocatalytic performances and activities of ZnAl2O4 nanorods loaded with Ag towards toluene

In this study, photocatalysts of ZnAl2O4 nanorods were obtained by adjusting pH values of the solution through hydrothermal routes, and then the Ag/ZnAl2O4 catalysts under pH = 6 were synthesized via loading different amounts of silver. Their structural properties were systematically investigated by SEM, TEM, XRD, BET, DRS, XPS and FTIR techniques. The photocatalytic performances and activities of the prepared samples and commercial P25 were comparatively studied by the degradation of gaseous toluene under UV irradiation in in situ FT-IR reactor. The results revealed that the prepared Ag/ZnAl2O4 nanorods with loading 1 wt.% Ag were more active than other prepared samples and commercial P25 in photocatalytic oxidation of gaseous toluene. Hydroxyl groups on the surface of Ag/ZnAl2O4 nanorods are able to react with photo-produced benzaldehyde, which is then retained on the catalyst surface leading to the progressive deactivation of the catalyst in the gas–solid system. The photocatalytic oxidation of gaseous pollutant over UV-illuminated Ag/ZnAl2O4 nanorods is a promising technique for air purification.

► Porous and “rod-like” ZnAl2O4 catalysts were synthesized by hydrothermal routes.
► Ag/ZnAl2O4 catalysts with loading silver were prepared by wet impregnation methods.
► Photocatalytic activities of the samples and P25 were comparatively studied by FTIR and GC.
► The removal ratio of toluene over Ag/ZnAl2O4 sample with loading 1 wt.% Ag is about 84.5%.