Synthesis and characterization of nitrogen and phosphorus co-doped TiO₂ nanoparticle anchored graphitic carbon nitride nanosheets: Photocatalytic application on dye removal

In this study, nitrogen and phosphorus co-doped titanium dioxide (NP-TiO₂) nanoparticles are anchored onto graphitic carbon nitride nanosheets (GCN) by the simple sonochemical method. The synthesized NP-TiO₂/GCN nanocomposites are characterized by UV–Visible absorbance spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, Photoluminescence spectroscopy, Scanning electron microscopy and Transmission electron microscopy. We find that the co-doping of nitrogen and phosphor to TiO₂ nanoparticles of size (10–25) nm as well as simultaneous anchoring onto GCN nanosheets. The optimised 2.5 wt% GCN in NP-TiO₂/GCN showed complete degradation of MB dye and MO dye at 105 min and 60 min respectively. The photocatalytic degradation performance is 5 times superior to that of individual NP-TiO₂ and GCN under visible light. The degradation rate constants of NP-TiO₂/GCN is found to be 0.01491 min⁻¹ for MB dye and 0.02153 min⁻¹ for MO dye. The improved photocatalytic performance of NP-TiO₂/GCN nanocomposite is due to the synergistic effects of both NP-TiO₂ and GCN, which decrease the bandgap as well as charge recombination.