Synthesis and electrocatalytic performance of N-doped graphene embedded with Co/CoO nanoparticles towards oxygen evolution and reduction reactions

N-doped graphene decorated with cobalt-based nanoparticles (Co/CoO/NG-T) were obtained via a 1,10-phenanthroline assisted pyrolysis method. The optimized Co/CoO/NG-800 showed excellent performance with E_{1/2, ORR} of 0.82 V vs. RHE and η_{OER, 10 mA cm-2} of 407 mV. A good stability was obtained with only 20 mV negative drift in the half-wave potential after 2000 cycles, and a retention rate of 94% after 5 h. The prominent performance is attributed to the electronic interaction between Co-based species and N-doped graphene, and the presence of active pyridinic-N moieties. This work provides a revealing paradigm on the design of efficient non-precious metal-based electrocatalysts.