Synthesis of large area graphitic carbon nitride nanosheet by chemical vapor deposition

The polymerization of graphitic carbon nitride (g-C₃N₄) into large single crystals has been particularly challenging. This study presents a quick and simple method to grow high quality two-dimensional graphitic carbon nitride nanosheets with a large domain size (up to 40 µm) on copper (Cu) foils. The chemical vapor deposition (CVD) method was used with melamine (C₃H₆N₆) as the source. Electron backscatter diffraction (EBSD) revealed that graphitic carbon nitride prefers a Cu(111) surface to a Cu(211) surface, which is consistent with the theoretical calculations. Moreover, it was demonstrated that the carrier gas is critical for the growth of graphitic carbon nitride. The use of noble Ar gas is recommended because it has a weaker etching effect compared to that of the more commonly used hydrogen (H₂) gas. Furthermore, CVD-grown high-quality graphitic carbon nitride films can be easily transferred onto other substrates for various applications, such as photodetectors or metal-free photocatalysts.