Enhanced Visible-Light Photocatalytic Degradation Efficiency of Ce4+ -Doped ZrO2/ZnO Nanocomposites Fabricated by a Simple Hydrothermal Method

We report a facile synthesis of Ce4+ -doped ZrO2/ZnO nanocomposites by a simple ultrasonic-assisted hydrothermal method. The ZrO2/ZnO:x mol% Ce4+ composites were then characterized by x-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller (BET), The zeta potential, energy dispersive x-ray spectroscopy (EDS), and elemental mapping, photoluminescence (PL) spectra, x-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy. The results indicated that the ZrO2/ZnO:x%Ce4+ composites have nanospherical morphology with average particle sizes less than 50 nm and bandgap values of 3.13-3.17 eV. The XPS spectrum confirmed the existence of a Ce4+/Ce3+ pair, which effectively prevents e(-)/h(+) recombination, contributing to the enhanced photocatalytic degradation of organic dyes of photocatalysts. The Ce4+-doped ZrO2/ZnO composites gave the high degradation, 66.88-91.23%, for Rhodamine B under visible-light irradiation.