Sulphur and nitrogen dual-doped mesoporous carbon hybrid coupling with graphite coated cobalt and cobalt sulfide nanoparticles: Rational synthesis and advanced multifunctional electrochemical properties

Doping-type carbon matrixes not only play a vital role on their electrochemical properties, but also are capable of suppressing the crush and aggregation phenomenon in the electrode reaction process for pristine metallic compound. Herein, graphite coated cobalt and cobalt sulfide nanoparticles decorating on sulphur and nitrogen dual-doped mesoporous carbon (Co@Co9S8/S-N-C) was fabricated by a combined hydrothermal reaction with pyrolysis method. Benefited from g-C3N4 template and original synthetic route, as-obtained Co@Co9S8/S-N-C possessed high specific surface area (751.7 m(2) g(-1)), large pore volume (1.304 cm(3) g(-1)), S and N dual-doped component and relative integrated graphite skeleton, as results it was developed as decent oxygen reduction electro-catalyst and ultra-long-life Li-ion battery anode. Surprisingly, compared with commercial Pt/C, it displayed a higher half-wave potential (0.015 V positive) and lower Tafel slop (66 mV s(-1)), indicating its superior ORR activities. Moreover, the ultra-long-life cyclic performances were revealed for lithium ion battery, exhibiting the retention capacities of 652.1 mAh g(-1) after 610 cycles at 0.2 A g(-1), 432.1 and 405.7 mAh g(-1) at 5 and 10 A g(-1) after 1000 cycles, respectively. We propose that the synergistic effect of structure and chemical component superiorities should be responsible for the remarkable electrochemical behaviors of the Co@Co9S8/S-N-C. (C) 2017 Elsevier Inc. All rights reserved.