Highly efficient and robust electrocatalysts have been in urgent demand for oxygen evolution reaction (OER). For this purpose

high-cost carbon materials

such as graphene and carbon nanotubes

have been used as supports to metal oxides to enhance their catalytic activity. We report here a new Co

3

O

4

-based catalyst with nitrogen-doped porous carbon material as the support

prepared by pyrolysis of porous polyurea (PU) with Co(NO

3

)

2

immobilized on its surface. To this end

PU was first synthesized

without any additive

through a very simple one-step precipitation polymerization of toluene diisocyanate in a binary mixture of H

2

O-acetone at room temperature. By immersing PU in an aqueous solution of Co(NO

3

)

2

at room temperature

a cobalt coordinated polymer composite

Co(NO

3

)

2

/PU

was obtained

which was heated at 500 ℃ in air for 2 h to get a hybrid

Co

3

O

4

/NC

consisting of Co

3

O

4

nanocrystals and sp

2

-hybridized N-doped carbon. Using this Co

3

O

4

/NC as a catalyst in OER

a current density of 10 mA·cm

-2

was readily achieved

with a low overpotential of 293 mV with a Tafel slope of 87 mV·dec

-1

a high catalytic activity. This high performance was well retained after 1000 recycled uses

demonstrating its good durability. This work provides therefore a facile yet simple pathway to fabrication of a new transition metal oxides-based N-doped carbon catalyst for OER with high performance.