S-doped g-C3N4 for fluorescence sensing of Fe3 + and photocatalytic dye degradation under solar light

Sulfur doped graphitic carbon nitride nanosheets were synthesized via polycondensation reaction of urea-thiourea mixture. Structure and morphology were characterized by XRD (X-ray diffraction), SEM (scanning electron microscope), and XPS (X-ray Photoelectron Spectroscopy). DRS (diffuse reflectance spectroscopy), PL (Photoluminescence spectroscopy) and time-resolved fluorescence decay spectra were used to study the optical characteristics. The photocatalytic dye degradation of Rhodamine B (RhB) in the presence of as-synthesized catalysts was investigated with the help of a UV–visible spectrophotometer. The photocatalytic activity of carbon nitride prepared from urea-thiourea mixture is almost three times higher than that of the pure sample. The detection of Fe3+ was also investigated by using the fluorescence sensing method. The as-synthesized samples hold greater selectivity and sensitivity for fluorescence sensing of Fe3+within a range of 0–3 µM. This range is comparable to the performance of other Fe3+ fluorescent probes previously reported.