Defect engineering for modifying transition metal oxides

Despite remarkable accomplishment of these transition metal oxides for electrocatalytic water splitting, the intrinsic activity, and durability of pristine electrocatalysts are still far from satisfactory. Among surface engineering strategies, defect engineering is considered to be an effective method to modify the surface properties and electronic structure of nanomaterials and has been widely used in electrocatalytic materials. Herein, recent advances regarding the type, synthetic methods, characterizations, roles of defects are systematically summarized, which may build the mechanism between defects and electrocatalytic performances. Finally, the challenges and prospects of defect engineering will be also discussed. This chapter may not only provide some guidelines to design and regulate electrocatalytic nanomaterials but also enlighten us to delicately boost the electrocatalytic performances for practical energy conversion devices.