Preparation of Fe-Doped Graphitic Carbon Nitride with Enhanced Visible-Light Photocatalytic Activity

A series of Fe-doped graphitic carbon nitride (g-C3N4) photocatalysts were prepared using ferric nitrate and melamine as precursors. X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), photoluminescence (PL) spectrum, and X-ray photoelectron spectroscopy (XPS) were used to identify changes in the characteristics caused by coordination of N atoms in the structural units of g-C3N4. The results indicate that embedded Fe changed the optical properties, affected the energy band structure, and increased the electron/hole separation rate. The activities of the Fe3+-doped g-C3N4 catalysts were tested in the photocatalytic degradation of rhodamine B (RhB) under visible light. The degradation rate of RhB over Fe-doped g-C3N4 was 99.7% in 120 min. The rate constant for Fe-doped g-C3N4 was 3.2 times as high as that of pure g-C3N4. Disodium ethylenediannine tetraacetate, tett-butyl alcohol, and 1,4-benzoquinone were used as hole (h(VB)(+)), hydroxyl radical (center dot OH), and superoxide radical (O-2(-center dot)) scavengers, respectively, to investigate the possible mechanism.