AUTHOR=Zhong Yongle TITLE=Ferroelectric polarization reversals in C2N/α-In2Se3 van der Waals heterostructures: a conversion from the traditional type-II to S-scheme JOURNAL=Frontiers in Chemistry VOLUME=11 YEAR=2023 URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2023.1278370 DOI=10.3389/fchem.2023.1278370 ISSN=2296-2646 ABSTRACT=

Introduction: Ferroelectric substances, characterized by inherent spontaneous polarization, can boost photocatalytic efficiency by facilitating the separation of photogenerated carriers. However, conventional photocatalysts with perovskite-class ferroelectricity are generally constrained by their 3D arrangement, leading to less accessible active sites for catalysis and a smaller specific surface area compared to a 2D layout.

Methods: In my research, I developed a 2D ferroelectric heterostructure consisting of C₂N/α-In₂Se₃. I performed first-principle calculations on the 2D C₂N/α-In₂Se₃ heterostructure, specifically varying the out-of-plane ferroelectric polarization directions. I primarily focused on C₂N/α-In₂Se₃ (I) and C₂N/α-In₂Se₃ (II) heterostructures.

Results: My findings revealed that reversing the ferroelectric polarization of the 2D α-In₂Se₃ layer in the heterostructures led to a transition from the conventional type-II [C₂N/α-In₂Se₃ (I)] to an S-scheme [C₂N/α-In₂Se₃ (II)]. The S-scheme heterostructure [C2N/α-In₂Se₃ (II)] demonstrated a high optical absorption rate of 17% in visible light, marking it as a promising photocatalytic material.

Discussion: This research underscores the significance of ferroelectric polarization in facilitating charge transfer within heterogeneous structures. It provides a theoretical perspective for developing enhanced S-scheme photocatalysts, highlighting the potential of 2D ferroelectric heterostructures in photocatalytic applications.