Although carbon nitride powder can

Although carbon nitride powder can be well prepared by solid-phase reaction, this method needs to be carried out under high temperature and high pressure, and the requirements on instruments and reaction conditions are very strict. Therefore, some researchers have improved the traditional solid-phase method to synthesize carbon nitride through a solid-phase reaction at a lower temperature and pressure. Gao et al. Used melamine as a nitrogen-containing precursor, acid-pretreated it, and then heat-treated it at 350 ° C in an air atmosphere to obtain a hollow tube g-C3N4 material. This method is simple and easy. The g-C3N4 nanotube has a length of millimeters, the diameter of the nanotube and the thickness of the tube wall are 300-500 nm and 20 nm, respectively, and have good fluorescence.