Ultrasonic-assisted preparation of novel ternary ZnO/AgI/Ag2CrO4 nanocomposites as visible-light-driven photocatalysts with excellent activity

This work reports ultrasonic-assisted preparation of novel ternary ZnO/AgI/Ag2CrO4 nanocomposites as excellent visible-light-driven photocatalysts. The ZnO/AgI/Ag2CrO4 nanocomposite with 20% of Ag2CrO4 has the superior activity in degradation of rhodamine B. Activity of this nanocomposite is nearly 167, 6.5, and 45-fold higher than those of the ZnO, ZnO/AgI, and ZnO/Ag2CrO4 samples, respectively. The ternary nanocomposite also showed enhanced activity relative to its counterparts for degradation of methylene blue and methyl orange as two dye pollutants under visible-light irradiation. The UV–vis DRS and PL spectra confirmed that the excellent photocatalytic activities are due to more visible-light absorption ability and efficiently separation of the charge carriers. Based on the effects of different scavengers, it was found that superoxide ions are the primary reactive species to cause the degradation reaction. Furthermore, the highly enhanced activity of the ternary nanocomposite was described using a proposed mechanism.