A S-Scheme MOF-on-MOF Heterostructure

摘要

Constructing MOF-on-MOF heterojunction with elaborate charge transfermechanism and interface is a promising strategy for improving thephotocatalytic properties of MOFs. Herein, a Step-scheme (S-scheme)MIL-125-NH_2@CoFe Prussian blue analogue (PBA) heterojunction is reportedfor the first time. The MOF-on-MOF heterostructure exhibits a sandwich-likemorphology with hollow CoFe PBA nanocages selectively assembled on thetop-down surfaces of MIL-125-NH_2 nanocakes. Experimental findings andtheoretical simulation results reveal the formation of internal electric field viainterfacial TiOCo bonds at the heterojunction, providing driving force andatomic transportation highway for accelerating the S-scheme charge transferand enhancing the redox performance. Contributed further by the hollowsandwich-like structures with increased active site exposure, the designedMOF-on-MOF heterojunction exhibits significantly enhanced photocatalyticactivity for degradation of various organic pollutants. This study providesinsights toward the rational design of semiconducting MOF-based heterojunctionswith improved properties.