One-pot Synthesis of Phosphorus Doped G-C3N4 with Enhanced Visible-light Photocatalytic Activity

Key Words:phosphorus; g-C3N4; visible-light; photocatalysis

Abstract:A series of P-doped g-C3N4 (P-CN) samples were prepared using urea (CO(NH2)(2)) and diammonium hydrogen phosphate ((NH4)(2)HPO4) as raw materials by a simple thermal condensation method. The surface morphologies and structures of the as-prepared samples were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscope (FT-IR), X-ray photoelectron spectroscope(XPS), scanning electron microscope (SEM), transmission electron microscope (TEM), UV-Vis diffuse reflection spectra (UV-Vis DRS) and N-2 adsorption-desorption isotherms, respectively. The visible-light photocatalytic property was demonstrated for photodegradation of Rhodamine (RhB) solution, and the photocatalytic mechanism for the P-CN samples under visible-light was tentatively proposed. The corresponding results indicate that C atoms in g-C3N4 are replaced by P atoms, which modifies the surface morphologies and electronic structures. The as-prepared P-CN samples show remarkably higher photocatalytic efficiency than pure g-C3N4 for RhB degradation under visible-light irradiation. 3%P-CN sample demonstrates the highest photocatalytic activity, which degrades 96.8% RhB after reaction for 30 min. The replacement of P to C atoms in g-C3N4 makes the surface of P-CN in an electron-rich state. Furthermore, the research indicates the conduction band of P-CN shifts to more negative values, which improves the reduction performance of photoelectron. The electrons in conduction band of P-CN reduce O-2 to center dot O-2(-) in the reaction system, so that the photocatalytic property are improved significantly.

Volume:32

Issue:2

Translation or Not:no