Construction, characterization, photochemical properties and the possible mechanism of Ag/AgBr/Ag3BiO3 composites

The AgBr/Ag3BiO3 composite photocatalyst was fabricated by one-step hydrothermal route. The as-obtained sample was systematically characterized by X-ray diffraction (XRD), UV-Vis diffuse reflectance (DRS), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM) and photoluminescence (PL) measurements. The photocatalytic activity was evaluated through degradation of the Methylene blue (MB) under visible light irradiation. Results illustrated that the Ag/AgBr/Ag3BiO3-5 (Ag/AgBr/ABO-5) exhibited the optimal performance, and the first-order rate constant (k(obs)) value of Ag/AgBr/ABO-5 was about 8.4 and 17.5 similar to fold than that of bare AgBr and Ag3BiO3, respectively. Trapping agent experiments indicated that the h(+) and center dot O-2(-) were dominative species for MB degradation. The results of PL proved that the electrons and holes can be separated effectively in the Ag/AgBr/ABO-5. In this work, type-I heterojunction was rendered to explain the transferring process, thus significantly enhancing photocatalytic reactivity of the composites. [GRAPHICS] .

Automated summary

In this study, AgBr/Ag3BiO3 composite photocatalyst was successfully prepared via one-step hydrothermal route and systematically characterized. The photocatalytic activity was evaluated through Methylene blue degradation test, showing that Ag/AgBr/ABO-5 exhibited optimal performance with effective separation of electrons and holes. The enhancement in photocatalytic reactivity was attributed to the type-I heterojunction mechanism employed in the transferring process.