Phosphorus doped graphitic carbon nitride (g-C 3 N 4 ) was easily synthesized using ammonium hexafluorophosphate (NH 4 PF 6 ) as phosphorus source, and ammonium thiocyanate (NH 4 SCN) as g-C 3 N 4 precursor, through a direct thermal co-polycondensation procedure. The obtained phosphorus doped g-C 3 N 4 was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (FTIR), UV–vi...