Highly dispersed CeO2–x nanoparticles with rich oxygen vacancies enhance photocatalytic performance of g-C3N4 toward methyl orange degradation under visible light irradiation

Abstract CeO2/g-C3N4 photocatalysts have attracted tremendous attention in the photocatalytic degradation of organic pollutants. The design and construction of highly active CeO2/g-C3N4 photocatalysts without harsh conditions is still challenged. Herein, highly dispersed CeO2–x nanoparticles with rich oxygen vacancies were successfully precipitated on the surface of g-C3N4 under mild conditions. The fabricated CeO2–x/g-C3N4 exhibits remarkable activity and stability for photocatalytic degradation of MO pollutant. The optimal rate constant of MO degradation over CeO2–x/g-C3N4 is about 0.031 min–1, which is three times higher than that of g-C3N4. A negligible activity decrease is observed after three cycling runs. The enhanced catalytic performance can be ascribed to the excellent dispersion of CeO2–x with rich oxygen vacancies that benefit O2 adsorption and visible light absorption. In addition, the proper band alignment between CeO2–x and g-C3N4 is conducive to the highly efficient separation of photogenerated electron-hole pairs.