Cu-doped mesoporous graphitic carbon nitride for enhanced visible-light driven photocatalysis

Abstract

A series of Cu-doped mesoporous graphitic carbon nitride (Cu/mpg-C₃N₄) photocatalysts with Cu introduced from 0.1 to 5 wt% were prepared using cupric chloride and melamine as precursors. The physicochemical properties of the synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), the N₂ adsorption technique, UV-Vis diffuse reflectance spectra (DRS), and photoluminescence spectra (PL). The results indicate that embedded Cu²⁺ changed the optical properties, affected the energy band structure, and increased the electron/hole separation rate. Subsequently, the photocatalytic activity of Cu/mpg-C₃N₄ was evaluated by methyl orange (MO) degradation under visible-light irradiation. The degradation rate of MO reached 90.2% in 120 min onto Cu²⁺-doped mpg-C₃N₄. The rate constant for Cu²⁺-doped mpg-C₃N₄ was 2 times as high as that of pure g-C₃N₄. These results should usefully expand the applications of mpg-C₃N₄ as a visible-light-driven photocatalyst.