Carbon Encapsulated Hollow Co3O4 Composites Derived from Reduced Graphene Oxide Wrapped Metal-Organic Frameworks with Enhanced Lithium Storage and Water Oxidation Properties.

Transition metal oxides have received great attention for boosting the performances for lithium-ion batteries and oxygen evolution reaction (OER). Here, hollow Co3O4 nanoparticles encapsulated in reduced graphene oxide (rGO) ( h-Co3O4@rGO) were synthesized through a two-step annealing process of graphene oxide wrapped zeolitic imidazolate framework-67 (ZIF-67@GO) precursors. By taking advantage of the enhanced conductivity, high dispersity, high surface area, and unique hollow morphology derived from the GO-wrapped protecting annealing strategy, the as-synthesized h-Co3O4@rGO composite not only exhibits a reversible capacity as high as 1154.2 mAh g-1 at 500 mA g-1 after 100 cycles and high rate performance (746 mAh g-1 at 3000 mA g-1) but also displays superior OER performance with an overpotential of 300 mV to obtain 10 mA cm-2.