Metallic silver modified SnO₂–Zn₂SnO₄ cube nanomaterials for improved photocatalytic degradation of rhodamine B

To modify the wide bandgap and intrinsic high recombination rate of photogenerated charge carriers of Zn₂SnO₄ photocatalysts, Ag/SnO₂–Zn₂SnO₄ composites were prepared by depositing Ag nanoparticles onto cube-shaped SnO₂–Zn₂SnO₄ nanomaterials via photoreduction. The composites were characterized by XRD, SEM, EDS, TEM, XPS, and UV–Vis DRS, and their photocatalytic degradation effect on rhodamine B (Rh B) for different Ag loadings was studied, with 10%Ag/SnO₂–Zn₂SnO₄ showing the greatest effect. The UV photocatalytic degradation rate of the Rh B solution reaches 100% after 12 min of visible light irradiation and 91% after five cycles. The free radical trapping agent experiment indicated that the active substances of Ag/SnO₂–Zn₂SnO₄ photocatalysis are ·O₂⁻ and h⁺. Further, photoelectrochemical tests revealed the higher electron–hole separation efficiency and faster charge transfer rate of the composites, enhancing the formation of photoproduced carriers and photocatalytic activity.