Luminescence and structure regulation of graphitic carbon nitride by electron rich P ions doping

Graphitic carbon nitride (g-C3N4) modified with electron rich P ions was synthesized by directly heating a mixture of melamine and diammonium hydrogenphosphate with various doping concentration. The effect of the doping ion and its concentration on the morphology, structural and optical properties of the samples were investigated in detail. With the doping concentration increasing, a relative red shift and broadening was observed in the luminescence spectra of the doped g-C3N4. Based on a series of structural characterization, it is found that P ions replace part of the C-lattice in the g-C3N4 network and form some P–N bonds. The P–N bonds affect the morphology and electronic structure of g-C3N4. Thus, the changes of luminescence properties could be mainly attributed to the doping-induced electronic redistribution.