CeO2 quantum dots anchored g-C3N4: synthesis, characterization and photocatalytic performance

Abstract Cerium dioxide quantum dots (CeO2QDs) modified graphitic carbon nitride (g-C3N4) was fabricated by a facile chemical reaction with urea and cerium nitrate hexahydrate as precursors. Combined X-ray diffraction (XRD), UV-Vis DRS, transmission electron microscopy (TEM), photoluminescence spectroscopy (PL), Electrochemical impedance spectra (EIS), Thermogravimetric analysis (TGA), Brunner-Emmet-Teller (BET) measurements and X-ray photoelectron spectroscopy (XPS) studies showing that CeO2QDs dispersed homogeneously on the g-C3N4 surface, which enhanced the absorption in visible light region. Specifically, we found that CeO2QDs/g-C3N4 shows much lower electron-hole recombination rate, and its Rhodamine B photodegradation rate constant can reach 0.00985 min-1, which is 7 times higher than that of single g-C3N4. In addition, the CeO2QDs/g-C3N4 displayed outstanding catalytic stability. Furthermore, the CeO2QDs/g-C3N4 catalyst also exhibited the excellent photodegradation performance on other substrates such as TC, Methyl Orange, and Methyl Blue. It was proposed that the CeO2QDs/g-C3N4 photocatalyst could follow a more appropriate Z-scheme charge transfer mechanism. Our studies extend the application of Quantum dots nanocomposite catalyst and pave the way for its further rational design.