GC/MS screening of buckthorn phytochemicals and their use to synthesize ZnO nanoparticles for photocatalytic degradation of malachite Green dye in water

Zinc oxide nanoparticles (ZnO NPs) were biosynthesized. According to GC/MS analysis, chalcone; the main phytochemical; is probably complexed with Zn ions that are then oxidized to ZnO NPs by atmospheric O-2 during heating. The ZnO NPs were characterized by TG, FTIR, XRD, FESEM, TEM, eEDAX, and BET surface area analysis. Sphere-like ZnO NPs were formed with 11 nm mean crystallite size, 5.2 m(2) g(-1) surface area, and 0.02 cm(3) g(-1) total pore volume. The synthesized ZnO showed excellent photocatalytic degradation (96.5 (perpendicular to) 0.24% in 1 hour at 25 degrees C) of malachite green (MG) in aqueous solutions under UV light at optimum conditions; pH 10, MG initial concentration of 20 mg L-1, and ZnO dose of 1.5 g L-1. Also, ZnO showed very good reusability (92.9 (perpendicular to) 0.2% after 5 runs). The experimental data obeyed pseudo-first-order kinetics (R-2=0.92). The photocatalysis process is dependent on the following species in the order: OH. > electron/positive hole pairs > O-2(center dot-). Moreover, photodegradation efficiency decreased in the presence of CO32-, HCO3-, and Cl-, but increased in the presence of NO3-, and SO42- ions. Thus, the green synthesized ZnO NPs can be applied as an efficient photocatalyst for the removal of MG from aqueous media.

Automated summary

Zinc oxide nanoparticles biosynthesized in this study showed excellent photocatalytic degradation of malachite green, with high efficiency and reusability. The photocatalysis process was found to be dependent on specific species and was affected by the presence of certain ions in the solution.