Nitrogen defect-regulated g-C3N4 to enhance the photocatalytic degradation performance of NO pollutants in cement mortar

Abstract

As environmental pollutants are being discharged in large quantities, developing a cheap and high-quality material for pollutant degradation is critical. This study developed a cement-based material with photocatalytic properties by combining photocatalytic micro- and nano-semiconductors with cement mortar. The structure of g-C3N4 was improved to enhance the interfacial transport properties of the photogenerated carriers by introducing nitrogen vacancies and mesopores. The photocatalytic ability and photocatalytic performance stability of the composite functional materials comprised cement mortar and modified g-C3N4 were evaluated. The results show that the intrinsic photocatalytic performance of the g-C3N4 photocatalyst can be improved by modification. Moreover, the purification rate of NO in the photocatalytic cement mortar is comparable to that of a pure g-C3N4 catalyst this proves that the internal environment of the cement mortar does not have any shielding effects on the intrinsic structure and catalytic active sites of the photocatalyst. Furthermore, the microstructures of the functional layer and mortar layer in the PFCMS system after condensation were observed using Leica and scanning electron microscopes. The results show that the photocatalyst was uniformly dispersed in the cement mortar but no obvious cracks were observed between the layers, indicating that the combination of photocatalyst and cement mortar was realized under the action of cement cementation, and the interlayer adhesion of the functional layer and the mortar layer was enhanced. This proves that the photocatalyst and cement mortar have good binding ability to play the photocatalytic role continuously.