Nitrogen-doped BiOBr nanosheets with preferentially exposed (102) facets enhanced visible-light photoreactivity

Abstract

In this work, N-doped BiOBr nanosheets were successfully prepared by using a novel high-shear mixer to facilitate uniform dispersion followed by a facile hydrothermal method, to evaluate the effects of N incorporation in BiOBr on photocatalytic performance of the as-prepared semiconductor catalysts for degrading organic contaminants. A significant facilitating effect was observed where the as-obtained N-doped BiOBr photocatalysts showed optimal photoreactivity for degrading organic wastewater compared to the undoped BiOBr when N atoms were uniformly incorporated into the BiOBr framework. In particular, 0.9N-BiOBr exhibited the top-flight performance for photocatalytic degradation of RhB, which was 15.3 times higher than the undoped BiOBr under visible-light irradiation (λ > 420 nm). Moreover, more crucial photogenerated active species for the photocatalytic degradation of RhB under visible-light irradiation, including superoxide radicals (O₂˙⁻) and photoinduced holes (h⁺) were obtained, which resulted in a significant increase in the photoreactivity and stability of 0.9N-BiOBr. Through a range of characterizations such as SEM, TEM, XRD, XPS, EIS and so on, the physicochemical structural properties of the as-prepared photocatalysts were investigated and revealed in detail. This work demonstrates that N doping in BiOBr can functionalize as an efficient regulator for BiOBr-based photocatalysts to enhance the photodegradation performance of organic contaminants such as organic dyes in an aquatic environment, and the results obtained in this work may provide insight into the design of general non-metallic doping strategies for potentially efficient and inexpensive photocatalysts.