Enhanced photocatalytic degradation of methylene blue using aluminum and cerium co-doped ZnO nanocomposite

Abstract Photocatalysis has emerged as an established and environmentally sustainable approach for degrading biological pollutants into less hazardous substances. In this work, zinc oxide (ZnO) nanorods co-doped with aluminum and cerium were produced via a single-step hydrothermal technique. The aluminum and cerium co-doped zinc oxide (ACZn) nanocomposite was investigated for structural, morphological, optical, and charge transfer kinetics by using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, UV–Vis diffuse reflectance spectroscopy, and photoluminescence spectroscopic techniques. The absorption spectra were perceived to be redshifted as a result of the increased absorption capacity of the ACZn-based photocatalyst due to the addition of Al and Ce. ACZn nanocomposite demonstrated a significantly enhanced photocatalytic efficiency (PE), achieving a 93% degradation of methylene blue (MB) under simulated solar irradiation, compared to CZn (89% PE), AZn (72% PE), and pristine ZnO (76% PE). This 22% improvement of ACZn relative to pristine ZnO was attributed to refined surface characteristics, decreased band gap energy, and enhanced charge separation efficiency, as demonstrated by kinetic analysis and photoluminescence investigations. Additional photocatalytic measurements disclosed several factors affecting the degradation process of methylene blue including photocatalyst dosage and initial dye concentration. Furthermore, the ACZn photocatalyst demonstrated a robust potential for environmental remediation applications by exhibiting superior reusability for multiple cycles without observing a noticeable decrease in photoactivity. Graphical abstract