Integrated CoO nanoparticles@porous carbon nanosheets arrays on carbon cloth as cathode for rechargeable Zn-air batteries

•A Mg(OH)2 template method is proposed to prepare hierarchical carbon electrode.•Combination of CoO nanoparticles and standing porous carbon arrays are required.•The hierarchical structure of air electrode promotes the transfer of reactants/products.•Zn-air battery shows superior performance with excellent durability and rate properties.