Construction of 2D-ZnS@ZnO Z-Scheme Heterostructured Nanosheets with a Highly Ordered ZnO Core and Disordered ZnS Shell for Enhancing Photocatalytic Hydrogen Evolution

Graphical Powered by the Sun : The formation of 2D-ZnS@ZnO Z-scheme heterostructures and introduction of zinc interstitial defects into ZnO was successfully achieved through a facile in-situ ion-exchange hydrothermal method. The photocatalysts exhibited high photocatalytic activity for hydrogen evolution. Heterostructure and defects in photocatalyst play highly important role in photocatalysis. Formation of 2D-ZnS@ZnO Z-scheme heterostructure and introduction of zinc interstitial defects into ZnO were successfully achieved through a facile in-situ ion-exchange hydrothermal approach, and the photocatalysts exhibited high photocatalytic activity for hydrogen evolution. The heterointerface between the highly ordered ZnO core and disordered ZnS shell, and the zinc interstitial, facilitate the transfer and separation of charge carriers, resulting in high photocatalytic activity. The 2D-ZnS@ZnO photocatalyst with a disordered ZnS layer of about 8 nm in thickness exhibited a photocurrent density about 7.2 times than that of ZnO, which is mainly attributed to the facilitative effect on interface transfer and the increased charge density. In addition, the photocatalytic activity can be adjusted via changing the thickness of the disordered ZnS overlayer. This work provides a strategy for the design of the heterointerface photocatalysts combined with defect engineering, through which the photocatalytic activity can be remarkably improved.