Photodegradation of Rhodamine B Photocatalyzed by Z-Scheme Plasmonic Ag/AgBr/Bi2MoO6 Heterojunctions

Z-scheme plasmonic photocatalytic Ag/AgBr/Bi2MoO6 nanocomposites were synthesized by precipitation deposition method and followed by sonochemical deposition method. Phase, morphology, chemical structure, surface area and optical properties of the products were characterized by different techniques. The analytical results reveal that the Z-scheme plasmonic nanocomposites were the co-existence of AgBr, Ag/AgBr and Bi2MoO6 to form heterostructure AgBr/Bi2MoO6 and Ag/AgBr/Bi2MoO6 nanocomposites. The surface of Bi2MoO6 nanoplates were fully covered with 10–15 nm spherical AgBr and Ag/AgBr nanoparticles. The DRS spectra were excellent absorption of visible light with absorption edges of 457 nm, 470 nm and 484 nm for Bi2MoO6, AgBr/Bi2MoO6 and Ag/AgBr/Bi2MoO6 nanocomposites, respectively. The visible-light harvest of Ag/AgBr/Bi2MoO6 nanocomposites was the highest due to the synergistic effect of Z-scheme Ag/AgBr/Bi2MoO6 heterojunctions and surface plasmon resonance (SPR) effect of metallic Ag nanoparticles. The photocatalytic activities were investigated through the photodegradation of rhodamine B (RhB) under visible radiation (λ ≥ 420 nm). Among the three different photocatalysts, Ag/AgBr/Bi2MoO6 nanocomposites have the highest decolorization efficiency of 97.37% within 80 min because of the formation of Z-scheme Ag/AgBr/Bi2MoO6 nanocomposites and excellent visible-light harvest.