Charge-transfer dynamics in S-scheme photocatalyst

Abstract

Natural photosynthesis represents the pinnacle that green chemistry aims to achieve. Photocatalysis, inspired by natural photosynthesis and dating back to 1911, has been revitalized, offering promising solutions to critical energy and environmental challenges facing society today. As such, it represents an important research avenue in contemporary chemical science. However, single photocatalytic materials often suffer from the rapid recombination of photogenerated electrons and holes, resulting in poor performance. S-scheme heterojunctions have emerged as a general method to enhance charge transfer and separation, thereby greatly improving photocatalytic efficiencies. This Perspective delves into the electron transfer dynamics in S-scheme heterojunctions, providing a comprehensive overview of their development and key characterization techniques, such as femtosecond transient absorption spectroscopy, in situ irradiated X-ray photoelectron spectroscopy and Kelvin probe force microscopy. By addressing a critical research gap, this work aims to trigger further understanding and advances in photo-induced charge-transfer processes, thereby contributing to green chemistry and the United Nations sustainable development goals. This Perspective presents the developments of S-scheme heterojunctions, including their origin, formation mechanism, material design, driving forces for charge-carrier transfer, application and future developments. In particular, it introduces the characterization methods used to study ultrafast charge-transfer dynamics.