From Mixed-Metal MOFs to Carbon-Coated Core-Shell Metal Alloy@Metal Oxide Solid Solutions: Transformation of Co/Ni-MOF-74 to CoxNi1-x@CoyNi1-yO@C for the Oxygen Evolution Reaction

Calcination of the mixed-metal species Co/Ni-MOF-74 leads to the formation of carbon-coated CoxNi1-x@CoyNi1-yO with a metal core diameter of similar to 3:2 rim and a metal oxide shell thickness of similar to,2.4 nm embedded imiforrnly in the ligand-derived Carbon matrix. The Close proximity of Co and Ni in the mixed -metal Co/Ni-MOF-74 promotes the metal alloying and the formation of a solid solution of metal oxide during the calcination process. The presence of the tightly coated -carbon shell. prohibits particle agglomeration and stabilizes the CoxNi1-x@CoyNi1-yO, nan opartides, in small size. The CoxNi1-x@CoyNi1-yO@C derived` -from Co/Ni-MOF-74 nanocomposites show superior performance for the oxygen :evolution reaction (OER). The use of mixed-metal MOFs as precursors represents a powerful strategy for the 113-rication of metaliallOy@metal oxide solid solution nanopartides in small size. This method also holds great promise in the development of multifiHnetional carbon-coated complex core-shell metal/metal oxides owing to the diversified MOF structures andd-their flexible chemistry