Formation and characterization of flower-like carbon nitride by pyrolysis of melamine

Flower-like carbon nitride with the diameters from 20 μm to 60 μm was synthesized by the high-energy ball-milling and twice thermal-annealing processes in a horizontal tube furnace. The as-prepared products were composed of nanocones radiating from the spherical central core, belonging to hexagonal crystal carbon nitride. The suitable annealing temperature and the second annealing improve remarkably the formation of the flower-like structure. This is the first time that the flower-like carbon nitride was synthesized in atmospheric environment. The photoluminescence spectra of the product show that a broad blue-violet emission peak centered at about 380 nm. The growth mechanism of the product is proposed.