Co-MOF-67 derived hollow double-shell core CoO with ZnCdS to construct p-n heterojunction for efficient photocatalytic hydrogen evolution.

It is an effective way to improve the photocatalytic hydrogen evolution activity by constructing a unique structure and tuning the morphology of catalysts. On the one hand, ZIF-67 was used as a precursor to prepare CoO derivatives with different morphologies [CoO (Porous Polyhedron) and CoOdb (Hollow Double-Shelled Polyhedron)]. The hollow polyhedron have the advantages of large specifie surface area, low density, stable three-dimensional spatial structure and excellent electron transport channels, which provide great advantages for the enhancement of photocatalytic activity in photocatalytic reactions. On the flip side, p-type CoO polyhedron and n-type ZnCdS nanoparticles are successfully coupled to construct a p-n heterojunction, which accelerated the transfer and separation of electrons and holes, thus enhancing the photocatalytic hydrogen production efficiency. Therefore, the composite catalyst (ZnCdS-CoOdb-20 %) exhibits excellent hydrogen evolution activity (33885 μmol·h·g), which is 9.17 times that of pure ZnCdS (3695 μmol·h·g) and 1.21 times that of ZnCdS-CoO-20 % (27903 μmol·h·g). This work provides a new idea for tuning the photocatalytic morphology to enhance the hydrogen evolution activity.