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

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 C 3 N 4 thin layer encapsulated lead-free Cs 3 Bi 2 Br 9 nanocrystals was constructed by electrostatic self-assembly method. This combination way does not disrupt the electronic, crystalline and structural properties of C 3 N 4 and Cs 3 Bi 2 Br 9 . Fluorescence quenching in C 3 N 4 /Cs 3 Bi 2 Br 9 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 C 3 N 4 and Cs 3 Bi 2 Br 9 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 .