Accelerated Photodegradation of Organic Pollutants over BiOBr/Protonated g-C3N4
Juanjuan Liu, Heng Guo, Haoyong Yin, Qiulin Nie, Shihui Zou
Abstract
Interfacial engineering has emerged as an effective strategy to optimize the photocatalytic activity of heterojunctions. Herein, the interface between graphitic carbon nitride (g-C3N4) and BiOBr was readily regulated by a protonation treatment. The synthesized BiOBr/g-C3N4 heterojunctions were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectroscopy. The results show that pretreating g-C3N4 in diluted HCl solution led to a partial protonation of g-C3N4, which ensured intimate contact and high dispersion of supported BiOBr without changing the surface area, bulk g-C3N4 structure, or visible light absorption. The abundant BiOBr/g-C3N4 interfaces remarkably improved the separation and transfer of photogenerated carriers, which produced more h+ and O2●− to accelerate the photocatalytic degradation of organic pollutants. The photocatalytic activities of the BiOBr/g-C3N4 heterojunctions were evaluated by the degradation of RhB under visible-light irradiation (λ ≥ 420 nm). The apparent reaction (pseudo-first-order) rate constant of BiOBr supported on partially protonated g-C3N4 (Bpg-C3N4-0.75) is ca. 3-fold higher than that of BiOBr supported on pristine g-C3N4 (Bg-C3N4), verifying interfacial engineering as an effective strategy to optimize the catalytic activity of heterojunctions.