Liuyang Zhang Emerging S-scheme Heterojunction Photocatalyst

Liuyang Zhang  Emerging S-scheme Heterojunction Photocatalyst

Photocatalytic technology is a kind of green technology that can utilize ubiquitous and intermittent solar energy and convert it into storable chemical energy. However, the serious recombination of photogenerated electrons and holes and the low oxidation/reduction ability of a single photocatalyst result in the low efficiency of photocatalysis. To solve the above problems, building heterojunction has become the most effective means.

Recently, Prof. Liuyang Zhang from China University of Geosciences (Wuhan) elaborated on the superiority and future directions of S-scheme heterojunction photocatalysts. This article covers state-of-the-art progress and provides new insights into its general design criteria. It starts with the challenges confronted by a single photocatalyst from the perspective of energy dissipation by borrowing the common behaviors in the dye molecule. Subsequently, other problems faced by a single photocatalyst are summarized. Then a viable solution for these problems is the construction of heterojunctions. To overcome the problems and mistakes of type-II and Z-scheme heterojunctions, S-scheme heterojunction is proposed and the underlying reaction mechanism is summarized. Afterward, the design principles for S-scheme heterojunctions are proposed and four types of S-scheme hetero-junctions are suggested. Following this, direct characterization techniques for testifying the charge transfer in S-scheme heterojunction are presented. Finally, different photocatalytic applications of S-scheme heterojunctions are summarized. Specifically, this work endeavors to clarify the critical understanding on the curved Fermi level in the S-scheme heterojunction interface, which can help strengthen and advance the fundamental theories of photocatalysis. Moreover, the current challenges and prospects of the S-scheme heterojunction photocatalyst are critically discussed

Figure 1. Four types of S-scheme heterojunctions: a) n-n junction; b) p-p junction; c) p-n junction; and d) n-p junction. CB, VB, and Ef represent the CB minimum, VB maximum, and Fermi level, respectively. This definition will continue to be used in the following paragraphs and figures.

The article was published in Advanced Materials under the title "Emerging S-scheme photocatalyst".

This research was supported by the National Natural Science Foundation of China. Prof. Jiaguo Yu is the corresponding author of this work, and the first author is Prof. Liuyang Zhang from China University of Geosciences (Wuhan).

Article link: https://onlinelibrary.wiley.com/doi/epdf/10.1002/adma.202107668