The fast degradation for tetracycline over the Ag/AgBr/BiOBr photocatalyst under visible light

A series of Ag/AgBr/BiOBr photocatalysts with different weight contents of Ag/AgBr were successfully constructed via a simple precipitation method in 80 °C water bath. Photocatalysts were characterized by XRD, XPS, SEM, TEM, N2 Adsorption-Desorption (BET), and UV–Vis Diffuse Reflectance Spectroscopy (DRS). Compared with BiOBr and Ag/AgBr, all the composite photocatalysts show the prominent photocatalytic activity for the degradation of tetracycline (TC). Especially, 1:5Ag/AgBr/BiOBr (20%) has the highest reaction rate constant (kapp = 0.20 min−1). Moreover, according to the results of radical scavengers runs, ·OH and h+ acted as the main reactive species in the degradation process. Based on above, a possible photocatalytic mechanism for organics degradation over Ag/AgBr/BiOBr was proposed. Interestingly, the redox cycle between O2/·O2− and Br−/Br0 assisted with the surface plasmon resonance (SPR) effect of silver dramatically promotes the separation and transfer of electron–hole pairs, and improves the photocatalytic activity of the as-obtained composite samples.