Thin Metal Organic Layers Derived Co/Co9S8/ N, S co-doped Carbon Nanosheets Oxygen Electrocatalysis synthesized by Space Confinement of Montmorillonite

A high effective bifunctional oxygen electro-catalyst plays a key role in Fuel Cell (FC), Metal-Oxygen battery and water splitting devices. In this paper, metal organic layers (MOLs) derived Co/Co9S8 nanoparticles coated by N, S co-doped graphene-like carbon nanosheets catalyst was synthesized with the help of the space-confinement effect of Montmorillonite (MMT). The as prepared material shows excellent electrocatalysis activity both for oxygen reduction and oxygen evolution reaction in 0.1 M KOH solution: its ORR onset potential is 0.93 V (vs. RHE) and limiting diffusion current density are 4.7 mA·cm-2. Moreover, the retention of current for the as-prepared material is 85% after stability test of 10000 s for ORR, while those of the template free catalyst and commercial Pt/C have glided to below 80%. And its tafel slope is 265 mV·dec-1, which is much smaller than its control sample, suggesting the excellent OER kinetics. The excellent catalytic activity and stability can be attributed to the relatively higher specific surface area, higher content pyridinic-N, Co-Nx active site and higher graphitization degree than the template free catalysts.