Design and fabrication of direct Z-scheme photocatalysts

Direct Z-scheme photocatalysts are composite semiconductor photocatalysts in which the charge transfer between the component semiconductors follows a Z-scheme pathway without the aid of additional electron mediators. Direct Z-scheme photocatalysts have provoked much attention in photocatalysis because of their capability to enhance redox potential and eliminate inactive electron–hole pairs of the photocatalytic system. For this reason, direct Z-scheme photocatalysts have been extensively exploited for various photocatalytic applications, ranging from solar fuel production to environmental remediation. In this chapter, the fundamental principles and development for the direct Z-scheme photocatalysts are described. General characterization methods for differentiating the direct Z-scheme photocatalysts from the conventional type-II photocatalytic system are also summarized. Then, the typical applications of the direct Z-scheme photocatalysts are elaborated. Finally, the challenges and future development directions for the direct Z-scheme photocatalysts are highlighted.