The preparation of high-quality two-dimensional materials with highly interesting properties and applications, such as graphene and graphene analogues, is a rapidly expanding research area. Herein, two-dimensional porous Co3O4 sheets with high uniformity were synthesized via a facile hydrothermal route. Various characterizations were performed to investigate this sheet-like structure. Owing to the desired promotion effects and multiple functionalities derived from this unique structure, the porous Co3O4 sheets present an enhanced photocatalytic performance in comparison with the bulk Co3O4 powder.