Investigation of the photocatalytic capabilities of green-synthesized CeO2–ZnO nanocomposites for degrading acid orange 7 dye under sunlight

Abstract This study investigates the production and photocatalytic activity of CeO 2 –ZnO nanocomposites, synthesized for the first time using Bacopa monnieri leaf extract to degrade the Acid Orange 7 Dye (AO7). The nanocomposites were successfully prepared using an extract from Bacopa monnieri leaves as a sustainable reducing agent. The characteristics of the CeO₂–ZnO nanocomposites were examined using UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), Brunauer–Emmett–Teller analysis (BET), field electron scanning electron microscopy (FE-SEM), cyclic voltammetry (CV), and photoluminescence spectrum (PL). Its large surface area (145 m 2 /g) and band gap (2.58 eV) greatly improved its capacity to absorb light. After 120 min, photocatalytic tests showed that it was able to degrade 93% of a sample of (AO7). The CeO 2 –ZnO nanocomposites large surface area and strong charge separation, together with the complementary interactions between CeO 2 and ZnO, are responsible for this high efficiency. These results demonstrate the potential of CeO 2 –ZnO nanocomposites as durable and effective photocatalysts for decomposing of organic dyes in wastewater treatment applications.