摘要
Main observation and conclusion A hybrid bifunctional oxygen reduction reaction(ORR)/oxygen evolution reaction(OER)NiCo_(2)O_(4-x)/NLG with rich pyridinic-nitrogen-cobalt coordination and oxygen vacancies was synthesized via a combination of the hydrothermal method and pulsed laser irradia-tion.NiCo_(2)O_(4-x)/NLG exhibits an excellent catalytic activity with a low overpotential of 290 mV at 10 mA.cm^(-2)for OER and a high half-wave potential of 0.85 V for ORR.As a result,the overall ORR/OER overpotential ofNiCo_(2)O_(4-x)/NLG is only 0.67 V in 1.0 mol/L KOH electrolyte,which is superior to commercial noble-metal-based catalysts(Pt/C+RuO2).It is evidenced that the enhanced intrinsic OER and ORR activities of NiCo_(2)O_(4-x)/NLG are attributed to a synergistic effect between the pyridinic-N-Co coordination and the oxy-gen vacancies.This work provides a new design strategy for enhancing the intrinsic activity of bifunctional ORR/OER electrocatalysts.
基金
the National Natural Stience Foundation of China(Nos.51822106 and 51572188).
