Photocatalytic Activity of Bi2O3 Enhanced by the Addition of Ce3+/Ce4+ Synthesized by Ethylene Glycol-assisted Solvothermal Method

The photocatalysts Bi2O3:Ce3+/Ce4+ (cerium content 0.2, 0.5, 0.8, and 1.1 wt. %) were prepared via one-pot ethylene glycol-assisted solvothermal method. The prepared x Ce-Bi2O3 (x=0.5, 0.8, 1.1) samples present delta-Bi2O3 phase with space group of Fm-3 m at room temperature, which indicates that the high-temperature cubic phase could be stabilized via Ce doping in Bi2O3 lattices. Moreover, the addition of Ce3+/Ce4+ could change the amount of oxygen vacancies (OVs) and adsorbed oxygen on the surface of photocatalysts. The existence of oxygen vacancies and adsorbed oxygen facilitated the generation of superoxide radicals () and hydroxide radicals (), which were the dominant reactive oxygen species for phenol degradation. The photocatalyst containing 0.8 wt. % cerium presented the highest photoactivity than the other synthesized samples. A photodegradation mechanism is proposed based on scavenger and electron spin resonance studies.