Charge transfer dynamics in C3N4 encapsulated Cs3Bi2Br9 nanocrystals heterojunction for photocatalytic application

• Published in: Journal of alloys and compounds Vol. 988; p. 174275
• Main Authors: Xu, Wei-Long, Hu, Jingli, Yang, Qiyan, Lian, Yuebin, Zheng, Min, Du, Erwei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2024
• Subjects: C3N4; Charge transfer; Cs3Bi2Br9; Heterojunction; Photocatalytic performance; C3N4; Cs3Bi2Br9; Charge transfer; Photocatalytic performance; Heterojunction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.174275

Perovskite materials have shown great application prospects in the field of photocatalysis due to their excellent photoelectric properties. However, the toxicity of lead and material instability limit its application. In this work, the heterojunction based on C3N4 thin layer encapsulated lead-free Cs3Bi2Br9 nanocrystals was constructed by electrostatic self-assembly method. This combination way does not disrupt the electronic, crystalline and structural properties of C3N4 and Cs3Bi2Br9. Fluorescence quenching in C3N4/Cs3Bi2Br9 composite is ascribed to the charge transfer process, which could be directly observed by spatially and temporally resolved fluorescence mapping image. The synergistic effect between C3N4 and Cs3Bi2Br9 can significantly improve the photocatalytic degradation efficiency of RhB, 98 % at 1 h. The stability of the composite was enhanced due to the special encapsulation effect. This work will provide a guideline for the construction of two-dimensional materials and perovskite heterojunction systems in the field of photocatalysis. •C3N4 encapsulated Cs3Bi2Br9 nanocrystals heterojunction was constructed.•The band alignment between C3N4 and Cs3Bi2Br9 favors charge transfer.•Charge transfer process was directly visualized by fluorescence lifetime mapping.•This special combination way is conducive to improving the stability of Cs3Bi2Br9.•Photocatalytic degradation efficiency of RhB for the composite reaches 98 % at 1 h.