Innovatively-synthesized CeO2/ZnO photocatalysts by sono-photochemical deposition: catalyst characterization and effect of operational parameters on high efficient dye removal

CeO 2 /ZnO with varied Ce 4+ mass ratios was synthesized as a stable and reusable photocatalyst using a sono-photochemical process in which CeO 2 crystals were formed and precipitated on the porous surface of ZnO nanosheets that had been pre-synthesized using the urea hydrolysis method. The synthesized photocatalysts were characterized through XRD, FTIR, BET, FE-SEM, and TEM techniques. The effects of light and ultrasonic irradiation on the removal of methylene blue (MB) as a contaminant component from deionized (DI) water were examined and the concentration of MB residue was measured using an UV–Vis spectroscopy after the treatment operation. The performance of the photocatalytic degradation was evaluated using a variety of operating parameters including catalyst composition (0–0.70 wt% Ce), initial dye concentration (10–30 ppm), catalyst loading (0.20–1.50 gr L −1 ), aeration by air flow (0–3.50 L min −1 ), pH (3–9.70), and also ultrasonic irradiation (80 kHz and 60 W). Results demonstrate that when the CeO 2 /ZnO with Ce/Zn mass ratio of 3 was employed instead of ZnO alone, the time of complete photocatalytic degradation lowered by almost 20%. Additionally, when the real water collected from Doroodzan dam, Fars, Iran with a total TDS of 540 ppm polluted with 20 ppm MB was treated with CeO 2 /ZnO (0.30 wt% Ce) nanosheets, MB was completely degraded after 8 min of the photocatalytic reaction. Furthermore, the ZCe3 could be used for the degradation process at least for 5 cycles with only a 12% reduction in MB degradation efficiency.