Journal of Power Sources, Vol.401, 55-64, 2018
Structural engineering of S-doped Co/N/C mesoporous nanorods via the Ostwald ripening-assisted template method for oxygen reduction reaction and Li-ion batteries
The long-debated intrinsic nature, less exposed active sites, as well as the tedious fabrication process of the metal-nitrogen-carbon structures severely impede the applications in the energy storage and conversion devices. Herein, we report a facile Ostwald ripening-assisted template method to controllably synthesize one-dimensional S-doped Co/N/C mesoporous nanorods as electrode materials for electrocatalytic oxygen reduction and Li-ions batteries. Introducing the S doping into the Co/N/C structure increases the intrinsic activity and electro-chemically active surface area, and the structural characteristics (e.g., the surface area, pore structure) of mesoporous nanorods are optimized on the basis of the Ostwald ripening effect for sufficiently exposing active centres and facilitating fast ion transport. Hence, it demonstrates efficient catalytic activity towards the oxygen reduction reaction in alkaline medium with the half-wave potential of 0.890 V vs. RHE, and even outerperforms the state-of-the-art Pt/C catalyst. In addition, as the anode material for Li-ion batteries, it also exhibits superior electrochemical performance with the specific capacity of 623.3 mAh g(-1) after 500 cycles at 1.0 A g(-1).
Keywords:Structural control;Metal-nitrogen-carbon;C-S-C;Synergistic effect;Oxygen reduction reaction;Li-ion batteries