Investigation of Crystallography and Charge Transfer Dynamics of CeO2–ZnO Nanocomposites Prepared via Facial Thermal Decomposition

Abstract

The ZnO and CeO₂ nanostructures were prepared via a thermal decomposition process. The CeO₂–ZnO nanocomposites with various CeO₂ quantities of 0–5 mol% characterized the structure, morphology, and optical characteristics using XRD, FT–IR, SEM, UV–Vis spectroscopy, and PL techniques. The phase fraction, lattice constants, and defects were determined by the calculation from the XRD result. The 5 mol% CeO₂–added ZnO sample exhibits the highest polar surface. SEM analysis revealed the presence of ZnO nanorods and CeO₂ nanoparticles. The composites principally featured ZnO with the spontaneous incorporation of CeO₂ nanoparticles. The bandgap was modified as CeO₂ content, showing 3.37 eV for ZnO and 3.31 eV for 5 mol% CeO₂ incorporation. Photoluminescence (PL) analysis demonstrated the Zn, Ce, and O defects and transformation of zinc interstitial (Zn_i) to Zn regular site (Zn_Zn). The photocatalytic degradation of Methylene Blue (MB) under visible light irradiation exhibited a superior efficiency than the single catalyst, determining the influence of charge transfer between the composite interfaces in combination with the sublevel energy of both Ce³⁺ and oxygen vacancy (V_o) being the center of electron trapping. This research points out the characteristics and the performance of thermal decomposition–processed CeO₂–ZnO composites in the photo-induced technology. The charge transfers were discussed, associating with the structural constants, emissive spectra, and sublevel energy.

Graphical abstract