$\mathrm{g}\text{-}{\mathrm{C}}_3{\mathrm{N}}_4/{\mathrm{TiO}}_2$ Photocatalyst and Its Performance of NO Degradation in Emulsified Asphalt

This study prepared one $\mathrm{g}\text{-}{\mathrm{C}}_3{\mathrm{N}}_4/{\mathrm{TiO}}_2$ composite photocatalyst by calcinating a mixture of melamine and nano ${\mathrm{TiO}}_2$, and then mixed it with asphalts to photodegrade the NO produced by automobile exhaust. The melamine and ${\mathrm{TiO}}_2$ were mixed uniformly at a mass ratio of $2:1$ and calcined at 550°C for 5 h. The microstructure of the $\mathrm{g}\text{-}{\mathrm{C}}_3{\mathrm{N}}_4/{\mathrm{TiO}}_2$ was investigated by a combination of Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The results indicate that there is no new phase formation in the composite photocatalyst, and ${\mathrm{TiO}}_2$ particles adhere to flaky $\mathrm{g}\text{-}{\mathrm{C}}_3{\mathrm{N}}_4$, which effectively reduces the agglomeration of ${\mathrm{TiO}}_2$ particles. The $\mathrm{g}\text{-}{\mathrm{C}}_3{\mathrm{N}}_4/{\mathrm{TiO}}_2$ powder was directly mixed with a neat asphalt and an emulsified asphalt separately to degrade the NO. It was found that the NO degradation efficiency of photocatalytic emulsified asphalt is better than that of photocatalytic neat asphalt.