Dual Functions of O-Atoms in the g-C<sub>3</sub>N<sub>4</sub>/BO<sub>0.2</sub>N<sub>0.8</sub> Interface: Oriented Charge Flow In-Plane and Separation within the Interface To Collectively Promote Photocatalytic Molecular Oxygen Activation
Yuehan Cao, Ruiyang Zhang, Qian Zheng, Wen Cui, Yang Liu, Kaibo Zheng, Fan Dong, Ying Zhou
Abstract
The photocatalytic performance of two-dimensional materials is largely limited by the fast recombination of photogenerated charges. Herein, we design and fabricate a novel g-C3N4/BO0.2N0.8 van der Waals heterostructure to realize oriented charge flow in-plane and separation within the interface. On one hand, a B–C bond forms within the g-C3N4/BO0.2N0.8 interface after the introduction of O atoms. The B–C bond as the mediator bridges g-C3N4 and BO0.2N0.8 sides to enhance the effective separation of photogenerated charges. On the other hand, the existence of O atoms promotes the formation of a B–O–O–B intermediate to realize that molecular oxygen can directionally obtain electrons from the surface to generate •O2–. As a result, BO0.2N0.8 instead of g-C3N4 is considered to be the main reaction side, and the energy barrier of NO3– generation is significantly decreased. The NO removal performance of g-C3N4/BO0.2N0.8 is enhanced and the NO2 generation is effectively controlled compared with that of g-C3N and g-C3N4/BN. This work could provide an effective and facile strategy to tune oriented charge transfer.