Heteroatom doping is effective to regulate electronic structure and improve the performance of photocatalyst. Herein, water oxidation on nitrogen-doped CeO2(1 1 0) was investigated by using density functional theory calculation to understand the role of nitrogen doping. The results show that the optimal pathway of water oxidation on perfect and nitrogen-doped CeO2(1 1 0) is H2O -> OH + H -> O + 2H; O + 2H + H2O -> OOH + 3H -> O-2 + 4H, and the rate-limiting step of whole water oxidation process is O + 2H + H2O -> OOH + 3H. The presence of nitrogen dopant in CeO2(1 1 0) induces new characteristic peak of impurity level, and reduces the activation energies of water oxidation, especially for the rate-limiting step of O-O bond formation. The reverse reaction of O and H to OH that is easily occur on perfect CeO2(1 1 0) is effectively prohibited on nitrogen-doped counterpart. Additionally, nitrogen dopant makes the rate-limiting step easier than that on oxygen-defective CeO2(1 1 0) from the kinetic perspective. Therefore, nitrogen-doped CeO2 is expected to be a promising photocatalyst for water oxidation. (C) 2018 Elsevier B.V. All rights reserved.