Co-enhancement of doped N and oxygen vacancies on the photocatalytic performance of ceria: Mechanism and influence of crystal faces

• Nitrogen doping and oxygen vacancies act synergistically to enhance the photocatalytic activity of ceria, as confirmed by experimental and DFT studies. • The exposed crystal face of CeO2 critically influences nitrogen incorporation, oxygen vacancy formation, and the resulting synergistic effect. • Rod-like nitrogen-doped CeO2 with exposed (110) face achieved 73.59% tetracycline degradation and 156.89 μmol/g hydrogen production, outperforming other photocatalysts. • Density functional theory simulations provided mechanistic insights into band structure, density of states, and oxygen defect properties, explaining the enhanced performance.