S-scheme quantum dots heterojunction photocatalysts: Assembly types, mechanism insights, and design strategies

Coupling quantum dots (QDs) in S-scheme (referred to as QD-S-scheme) is an efficient approach for photocatalysis. However, a comprehensive review of S-scheme QDs heterojunction photocatalysts is, to the best of our knowledge, absent. Herein, a concise overview of the unique advantages and limitations of QDs in photocatalytic reactions, as well as the charge transfer mechanism of the S-scheme is first introduced. Secondly, a thorough summary and evaluation of the types and assembly strategies of QDs are presented, highlighting the pivotal role of the QD-S-scheme heterojunction interface in photocatalytic performance. Then, the characterization methods for the charge transfer from the bulk to the interface and surface are discussed from the perspectives of the built-in electric field (BEF), steady-state and transient charge transfer processes, and photochemical reactions. And the design principles and optimization strategies for surface modulation, interface construction, and heterojunction design are also illustrated. Finally, insights on the current research status, challenges, and prospects of the QD-S-scheme are presented to contribute the development of QD-S-scheme heterojunction photocatalysts.