ZIF ‐67 derived hollow double‐shell core Co 3 O 4 modified g‐C 3 N 4 to construct p‐n heterojunction for efficient photocatalytic hydrogen evolution

The imidazolium salt zeolite framework (ZIFs) organometallic framework materials have the advantages of high stability and controllable structure and are excellent materials for preparing photocatalytic semiconductors. In this study, the regular dodecahedron material ZIF-67 was used as the substrate, and the intermediate was calcined after the substrate adsorbed Co-based metal clusters to obtain Co3O4 with a hollow double-shell structure. Through SEM and fluorescence detection, it can be seen that the Co3O4 material obtained by this method not only has a unique spatial morphology but also shows a strong light absorption performance and a high charge transfer rate. In addition, graphite-like phase carbon nitride (g-C3N4), as a traditional catalyst, has been unable to move toward industrialization due to its low electron utilization and light absorption properties. So here, the composite catalyst CNCO-x (x = 1, 2, 2, 3, 4, and 5) was prepared by simply anchoring Co3O4 and g-C3N4 to improve the catalytic performance of g-C3N4. The results show that the introduction of Co3O4 not only improves the electron utilization of g-C3N4 but forms a charge transfer bridge channel (p-n heterojunction) after contact between the two, which effectively promotes the rapid transfer of photoelectrons between the contact interfaces. Finally, when the amount of Co3O4 introduced is 15%, the amount of hydrogen produced in 5 hours can reach 0.163 mmol (3.26 mmol g−1 hour−1), which is 163 times that of pure g-C3N4.