Vertical interface coupling between crystalline a-Fe2O3 and carbon nitride nanosheets for efficient degradation of organic pollutants

The interface coupling of crystalline catalytic materials exhibits unique functions in removing pollutants and purifying water resources; however, little attention has been paid to the effect of different crystal surface coupling on photogenerated charge separation. In this study, different coupling facets of alpha-Fe2O3 were constructed on cyclized carbon nitride (ACN) by impregnation hydrothermal method, and the coupling mechanism of alpha-Fe2O3 crystal facets on ACN was explained. The alpha-Fe2O3 nanosheets can be assembled parallelly or vertically on the surface of ACN due to the surface energy of alpha-Fe2O3 crystal facets and the different surface charges of ACN. The Z-scheme heterojunction formed by different interface coupling between alpha-Fe2O3 and ACN improved the separation efficiencies of photogenerated carriers. The photodegradation of organic pollutants and antibiotics showed that the photoactivity of Fe110/ACN+ was much higher than that of ACN, ACN+ and Fe001/ACN. The maximum removal rate of oxytetracycline by Fe110/ACN+ composites was 88.6%, and it had excellent adsorption and catalytic effect on organic dye Congo red within 120 min. Overall, the work may provide a new perspective for designing structures of unique crystal surface coupling and constructing heterojunctions with high catalytic performance.

Automated summary

This study investigates the effect of different crystal surface coupling on photogenerated charge separation by constructing different coupling facets of alpha-Fe2O3 on ACN. The Z-scheme heterojunction formed by different interface coupling between alpha-Fe2O3 and ACN enhances the separation efficiencies of photogenerated carriers and exhibits high catalytic performance.