Upgrading of g-C3N4 semiconductor by a Nitrogen-doped carbon material: A photocatalytic degradation application

The synthesis of a cheap, nonmetallic and active photocatalyst is the target of this study. Several Carbon loadings (0.2, 0.5 and 1 wt%) were incorporated into the graphitic carbon nitride (g-C3N4) semiconductor by a simple wet impregnation method. Temperature treatment was used for composite photocatalyst activation. The catalysts and their precursors were characterized by N2 sorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV–vis) and Raman spectroscopy. The sample composed of 0.5 wt% N-Carbon/g-C3N4 treated 2 h at 500 °C revealed the best performance by showing the highest degradation efficiency of methylene blue (MB) (90% in 3 h using solar light simulator). The optimal amount of catalyst in the medium was determined to be 1 g/L. The high activity of the treated 0.5 wt% N-Carbon/g-C3N4 catalyst was ascribed to an improvement in the electrochemical properties of the bulk g-C3N4 as a result of the inclusion of nitrogen-doped carbon in its core structure. The intensification of conductivity and the improvement in the electrochemical properties was explained by the formation of carbon-like graphitic structure doped with pyridinic and pyrrolic nitrogen groups under heat treatment. The high activity, stability, low cost and non-toxicity of this material prove the high potential of this technology for water purification and other related fields.