Photocorrosion Inactivation of Ag2O/TiO2 Photocatalysts and the Inhibition Effect of Alkaline Conditions on the Inactivation

In this paper, we prepared P-N type Ag 2 O/TiO 2 heterojunction photocatalysts via the precipitation method and found that their photocatalytic performance significantly declined after cyclic use. To understand the inactivation mechanism, we analyzed the photocatalyst samples using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron spin resonance spectroscopy (ESR), and inductively coupled plasma spectroscopy (ICP) during the recycling process. Our results showed that the Ag 2 O content in the composite photocatalyst decreased sharply, and the characteristic peak intensity of the {111} crystal plane of Ag 2 O in the photocatalyst gradually decreased. Based on these findings, we proposed a mechanism for the inactivation of Ag 2 O/TiO 2 and investigated the inhibitory effect of the pH of the reaction solution on inactivation. We observed that the photocatalyst’s inactivation was significantly inhibited at pH = 12. Overall, our study clarifies the inactivation mechanism of Ag 2 O/TiO 2 photocatalysts and proposes a method to inhibit inactivation, which could provide valuable references for future research on Ag 2 O-based photocatalysis.