The Effect of Different g-C3N4 Precursor Nature on Its Structural Control and Photocatalytic Degradation Activity

Due to its good visible-light photocatalytic activity and environmental friendliness, g-C3N4 has attracted much attention. The relationship between precursor type and the properties of obtained catalysts is interesting to investigate. In this work, target catalysts were prepared via the thermal polymerization of different precursors, melamine, a mixture of urea and melamine, and a mixture of melamine and cyanuric acid. The prepared g-C3N4 were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), and scanning electron microscopy (SEM). Through the characterization and analysis, the adjusting of precursors could result in the change of the microstructure. The maximum BET surface area was 98.04 cm3g−1 through precursor controlling, more than eight times that of MCN (11.15 cm3g−1) using melamine as precursor. The thermal decomposition process was also analyzed to discuss the interaction and polymerization with precursor controlling. The introduction of melamine and cyanuric acid with melamine as precursors led to the formation of a special nanotube structure and additional function groups on the surface of g-C3N4 to increase the photocatalytic activity.