Facile Formation of Bi2O2CO3/Bi2MoO6 Nanosheets for Visible Light-DrivenPhotocatalysis

摘要

Bi2O2CO3/Bi2MoO6 heterojunction catalysts were prepared by treating Bi2MoO6 sheets with aqueous NaHCO3 solutions at room temperature. All the Bi2O2CO3/Bi2MoO6 heterojunctions exhibited higher activities than pristine Bi2MoO6 in the photocatalytic degradation of rhodamine B (RhB), methyl orange, and ciprofloxacin under visible-light irradiation, and the most active photocatalyst was found to be the one with a C/Bi molar ratio of ∼1/2.3. Relevant samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, Fourier transform infrared spectroscopy, and UV–vis spectroscopy. The higher activity of Bi₂O₂CO₃/Bi₂MoO₆ than pristine Bi₂MoO₆ is explained by the enhanced separation and transfer of photogenerated electron/hole pairs, as verified by transient photocurrent densities, photoluminescence spectroscopy, and electrochemical impedance spectroscopy. Photogenerated holes (h⁺) and superoxide radical anions (^•O₂^–) were found to be the main activespecies. The good reusability of Bi₂O₂CO₃/Bi₂MoO₆ was testified by cycling degradationof RhB and tetracycline hydrochloride.