Noble metal-free core-shell CdS/iron phthalocyanine Z-scheme photocatalyst for enhancing photocatalytic hydrogen evolution

Improving the separation efficiency of photogenerated carriers and broadening the light absorption range of the photocatalyst are two important factors for improving the performance of the photocatalyst. In this paper, a new and efficient Z-scheme CdS/iron phthalocyanine (CdS/FePc) core-shell nanostructure composite material is prepared by a simple solid-phase reaction method. There are two key points in the preparation of composite materials: one is that hydrogen bonding energy is closely connected with FePc, another is that FePc can be uniformly assembled on CdS nanoparticles. The photocatalytic hydrogen evolution (PHE) of the CdS/FePc nanocomposite (73.01 μmol/h) is 2.6 times higher than that of pure CdS (26.67 μmol/h). In addition, after 4 photocatalytic cycles, the PHE of the CdS/FePc composite is still 92.3% of the first cycle. There are three reasons for this situation: (1) The Z-scheme heterojunction is formed to improve the separation efficiency of photogenerated carriers; (2) FePc expands the visible light absorption range of CdS; (3) The large core-shell contact area is favorable for the separation of photo-induced carriers at the interfaces. This research is conducive to the further development of new photocatalytic materials with high efficiency, low cost and simple preparation.