In situ growth of metal organic frameworks derived hierarchical hollow porous Co3O4/NiCo2O4 nanocomposites on nickel foam as self-supported flexible electrode for methanol electrocatalytic oxidation

Most of the metal organic frameworks (MOFs) derived metal oxides are powdery, which cannot be directly used for electrocatalysis. In this report, zeolitic imidazole framework-67 (ZIF-67) derived hollow porous Co3O4 nanospindle arrays were in situ grown on nickel foam (NF) substrate (NF/Co3O4) and used as 3D skeleton. Cobalt nickel-aspartic acid coordination precursors (CoNi-Asp) derived NiCo2O4 nanotubes were in situ grow on the NF/Co3O4 3D skeleton to formed the hierarchical hollow porous self-supported flexible NF/Co3O4/NiCo2O4 electrode, which can be directly used for methanol electrocatalytic oxidation. The 3D Co3O4 skeleton can not only afford more surface area and strong adhesion for the in situ growth of NiCo2O4 nanotubes but also enhance the activity of NiCo2O4. More strikingly, the NF/Co3O4/NiCo2O4 exhibited good flexibility, which have potential application in flexible direct methanol fuel cell (DMFC).