Facile synthesis of organic–inorganic layered nanojunctions of g-C3N4/(BiO)2CO3 as efficient visible light photocatalyst

Abstract

Novel g-C₃N₄/(BiO)₂CO₃ organic–inorganic nanojunctioned photocatalysts were synthesized by in situ depositing (BiO)₂CO₃ nanoflakes onto the surface of g-C₃N₄ nanosheets through a one-pot efficient capture of atmospheric CO₂ method at room temperature. The as-synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectroscopy (DRS), N₂ adsorption–desorption analysis and electron spin resonance (ESR). The photocatalytic activity of as-synthesized samples was evaluated by degrading Rhodamine B (RhB) and phenol in aqueous solution under visible-light irradiation. The g-C₃N₄/(BiO)₂CO₃ nanojunctions showed much higher visible-light photocatalytic activity than those of pure g-C₃N₄ and (BiO)₂CO₃ for the degradation of RhB and phenol. The enhanced photocatalytic activity can be mainly ascribed to the well-matched band structures, dye photosensitization and efficient crystal facets coupling interaction between g-C₃N₄ {002} and (BiO)₂CO₃ {002}. The ˙O₂⁻ radicals were identified as the main active species. Furthermore, the pure (BiO)₂CO₃ with highly exposed {002} crystal facets also exhibited excellent visible-light photoactivity for the degradation of RhB, which can be originated from the indirect dye photosensitization. The present work could provide a new strategy for the efficient utilization of atmospheric CO₂ in green synthetic chemistry.