Z-Scheme 2D/2D α-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 (α-Fe2O3) are used to prepare a Z-scheme 2D/2D α-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 α-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 α-Fe2O3 nanoplates. Cycling experiments verify that the α-Fe2O3/g-C3N4 heterojunction has good stability and reusability. The α-Fe2O3/g-C3N4 heterojunction therefore has great potential in sustainable and efficient pollutant degradation.