Nano heterojunction of double MOFs for improved CO2 photocatalytic reduction performance

Metal-organic frameworks (MOFs), featuring semiconductor-like behavior, are promising for the photocatalytic reduction of CO2. While their practical application is hindered by the disadvantages of low charge migration efficiency and fast electron-hole pair complexation. In this paper, a simple solvothermal method was used to load NH2-UiO-66 onto the surface of MIL-101(Cr) to form a nano type II heterojunction double MOFs composite of NH2-UiO-66 @MIL-101. The results show that the heterostructure of NH2-UiO-66 @MIL-101 promotes the separation of photogenerated electron-hole pairs and accelerates the interfacial photogenerated electron transfer under light, and the NH2-UiO-66 @MIL-101 type II heterojunction exhibits higher activity for photocatalytic reduction of CO2 compared with pure MIL-101(Cr) and NH2-UiO-66. In addition, the possible photocatalytic mechanism was further elucidated to demonstrate the increased photocatalytic activity of NH2-UiO-66 @MIL-101. This study provides effective insights for designing efficient MOFs photocatalysts for CO2 reduction to enhance the photocatalytic activity for environmental protection and governance.