Construction of g-C₃N₄-mNb₂O₅ Composites with Enhanced Visible Light Photocatalytic Activity.

A series of composites consisting of g-C₃N₄ sheet and mesoporous Nb₂O₅ (mNb₂O₅) microsphere were fabricated by in situ hydrolysis deposition of NbCl₅ onto g-C₃N₄ sheet followed by solvothermal treatment. The samples were characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), N₂ adsorption-desorption, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence spectroscopy (PL). The photocatalytic activity of the composites was studied by degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) in aqueous solution under visible light irradiation ( > 420 nm). Compared with g-C₃N₄ and mNb₂O₅, g-C₃N₄-mNb₂O₅ composites have higher photocatalytic activity due to synergistic effect between g-C₃N₄ and mNb₂O₅. Among these composites, 4% g-C₃N₄-mNb₂O₅ has the highest efficiency and good recyclability for degradation of both RhB and TC-HCl.