Characterisation Analysis of Sulphur and Phosphorous Doped and Co-doped Graphitic Carbon Nitride (g-C3N4) Materials

Abstract

Graphitic carbon nitride (g-C₃N₄) is tailored with doping of different non-metals (Sulphur and Phosphorus). For synthesis through thermal condensation method, the mixtures of urea and dopant with diverse concentrations have been added for preparation of materials. The basic effect of doping and its concentration on the structural morphology and absorption spectra of the samples is investigated in detail. Pure g-C₃N₄ suffers from high recombination rate of photogenerated electron-hole pairs resulting in low photocatalytic activity. Different techniques like X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) spectroscopy, and Photoluminescence spectroscopy (PL) have been used for the characterization. X-ray diffraction studies confirm the formation of the g-C₃N₄ structure and SEM images reveal crumpled sheets and irregular plate like shapes of the doped graphitic nitride samples. FTIR analysis identify the presence of surface amino (N-H) and water (O-H) groups, cyano terminal group (C≡N), (C≡C), C–N) and (C=N) bonds and breathing mode of the tri-s-triazine units in the samples. PL spectra shows that the sulphur and phosphorus co-doped PSGCN (8 wt.%) sample is better for photocatalytic activity.