Z-Scheme 2D/2D alpha-Fe2O3/g-C3N4 heterojunction for photocatalytic oxidation of nitric oxide

Heterojunctions have attracted considerable attention for efficiently utilizing solar energy and improving conversion efficiency during pollutant degradation. Herein, carbon nitride and hematite (alpha-Fe2O3) are used to prepare a Z-scheme 2D/2D alpha-Fe2O3/g-C3N4 heterojunction using an impregnation-hydrothermal method. The unique 2D/2D structure has a high interfacial area and widely-dispersed active sites. The energy band structure of the Z-scheme heterojunction leads to broad visible-light absorption and promotes charge transfer. Optimizing the content of the alpha-Fe2O3 precursor in composite leads to a maximum efficiency of 60.8% for the removal of 600 ppb of NO, which is approximately 1.78 times that of g-C3N4 (34.2%). The photocatalytic performance is greatly promoted because of the formation of the heterojunction and the strong interfacial action between g-C3N4 nanosheets and alpha-Fe2O3 nanoplates. Cycling experiments verify that the alpha-Fe2O3/g-C3N4 heterojunction has good stability and reusability. The alpha-Fe2O3/g-C3N4 heterojunction therefore has great potential in sustainable and efficient pollutant degradation.

Automated summary

The Z-scheme 2D/2D α-Fe2O3/g-C3N4 heterojunction prepared by impregnation-hydrothermal method shows efficient photocatalytic degradation of pollutants with high stability and reusability. The unique structure with high interfacial area and widely-dispersed active sites leads to broad visible-light absorption and promotes charge transfer, resulting in significantly improved efficiency for NO removal compared to g-C3N4 alone.