New Synthetic Route for the Growth of α-FeOOH/NH2-Mil-101 Films on Copper Foil for High Surface Area Electrodes

A novel metal organic framework (MOF)-based composite was synthesized on a Cu substrate via a two-step route. An amorphous iron oxide/hydroxide layer was first deposited on a Cu foil through a sol-gel process; then, Fe-NH2-Mil-101 was grown using both the iron oxide/hydroxide matrix, which provided the Fe3+ centers needed for MOF formation, and 2-aminoterephthalic acid ethanol solution. This innovative synthetic strategy is a convenient approach to grow metal oxide/hydroxide and MOF composite films. Structural, chemical, and morphological characterizations suggest that the obtained composite is made up of both the α-FeOOH goethite and the NH2-Mil-101 phases featuring a hybrid heterostructure. The electrochemical features of the composite structure were investigated using electrochemical impedance spectroscopy. The impedance behavior of the α-FeOOH/NH2-Mil-101 films indicates that they can be used as efficient high surface area metal hydroxide/MOF-based electrodes for applications such as energy storage and sensing.