Synthesis, analysis, and application of zinc oxide and bismuth-based nanocomposites (ZnO/BaBi2O6) as a photocatalyst for organic dyes degradation

In this study, a new binary heterostructure nanocomposite ZnO/BaBi2O6 was synthesized to improve the degradation rate of methyl orange, rhodamine B, and eosin dyes. ZnO and BaBi2O6 were prepared by simple, economical, and natural-friendly ultrasonic and hydrothermal methods. The reflux method was used to form a composite of these two nanoparticles. The ZnO/BaBi2O6 (30 %) sample showed the best performance among all the percentage combinations. The optimal sample was able to eliminate more than 95 % of the methyl orange dye concentration in 40 min. The constant rates of the ZnO/BaBi2O6 (30 %) sample for methyl orange (MO), rhodamine B (RhB), and eosin were 88, 9.94, and 9.8 times more than pure ZnO, respectively. The prepared samples were analyzed by techniques: XRD, XPS, FESEM, EDX, FT-IR, BET, UV-vis, DRS, and PL. The band gap energy of the novel nanocomposite was calculated using the Tauc plot method. For ZnO and ZnO/BaBi2O6 (30 %), the band gap energy was 3.24 and 2.89 eV, respectively. Scavenger tests showed that h+ and center dot O-2(-) play the main role in dye degradation. The recycling test demonstrated that the resulting composite remained stable after five use runs. A possible photocatalytic reaction mechanism was proposed to understand the process.