Core-shell dual-MOF heterostructures derived magnetic CoFe2O4/CuO (sub) microcages with superior catalytic performance

The high performance of catalysts relies largely on the meticulous design of hierarchical hollow micro/nanostructures with more active sites and superb structural tenability. Herein, we developed a simple strategy to design and fabricate CoFe2O4/CuO (sub)microcages using core-shell dual-MOF heterostructures (Fe-II-Co PBAs@HKUST-1) as both the precursor and self-sacrificing template. The derivation of metal oxide composites from dual-MOF heterostructures is challenging, and this method could overcome the difficulty caused by the possible lattice mismatch between the different MOFs. Uniform core-shell dual-MOF structures Fe-II-Co PBAs@HKUST-1 were first fabricated and then converted to CoFe2O4/CuO (sub)microcages by thermal annealing in air. The resulting CoFe2O4/CuO (sub)microcages were extensively characterized and exhibited remarkable catalytic performance with an excellent stability and magnetic recyclability for the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. In addition, CoFe2O4/CuO (sub)microcages were also found to be highly active for catalytic reduction of methylene blue (MB) by NaBH4 in an aqueous solution. The results show that CoFe2O4/CuO (sub)microcages have potential application for organic pollutants degradation and environmental rehabilitation.