Mechanistic insights into the influence of surface ligands on quantum dots for photocatalysis

Quantum dots are promising semiconductor nanocrystals in the field of photocatalysis owing to their unique properties in contrast to bulk semiconductors. Surface ligands, the molecules or ions connected to quantum dots, are indispensable components for intact colloidal quantum dots. They play important roles in influencing various physical and chemical properties of quantum dots. Therefore, understanding the structure of surface ligands and their specific mechanism for the photocatalytic process of quantum dots is of great significance. In this paper, the typical classification, the common characterization techniques and the function of surface ligands are first reviewed in brief. This provides a general understanding of surface ligands, which is a prerequisite for revealing their possible impact on the photocatalytic processes. Influences of surface ligands of quantum dots on photocatalysis are then discussed in detail from four aspects: adjustment of the band energy structure, the charge transfer and separation process, the surface reaction process as well as photocatalytic stability. In the end, we summarize the current research progress and potential research directions in this field, which could give the readers clues for future study.