Efficient bimetallic (Ni, Co) carbonate hydroxide (NiCo-LDHs) electrocatalysts for the oxygen evolution reaction were prepared using an Ar plasma exfoliation strategy. Smooth 1D nanowires of NiCo-LDHs were delaminated into thin nanosheets to form three-dimensional dendritic structures. Furthermore, the electrochemical active surface area was significantly increased and more higher oxidation states were exposed during this process. The exfoliated NiCo-LDHs exhibited a lower onset potential, much higher current density and longer stability.