Abstract
Pyrite-type sulfides(PTS)exhibit promising intrinsic activities for oxygen reduction and evolution re-actions(ORR/OER).However,their poor electrical conductivities may limit the charge transfer rate to inevitably lower activity.Here,yolk-shell structured cobalt-pyrite nanospheres(CoS2 YSS)are prepared and modified with amino groups as nucleation sites for coupling highly-conductive needle-like nitrogen-doped carbon via a facile solvothermal method(CoS2 YSS@NC).The as-marked CoS2 YSS@NC-0.5 shows a gap between yolk and shell,and an obvious exterior layer of grafted NC,which can provide an inte-grated structure,an interior place,and three exposed surfaces on CoS2.CoS2 YSS@NC-0.5 reveals higher ORR activity(half-wave potential of 0.88 V)and methanol resistance than commercial Pt/C.Due to in-situ formation of highly-active CoOOH,CoS2 YSS@NC-0.5 shows a better overpotential(244mV at 10mA/cm2)and Tafel slope(135mV/dec)than RuO2.Zinc-air battery with CoS2 YSS@NC-0.5 air-cathode exhibits good open circuit potential(1.44 V),specific capacity(772.5 mAh/g)and cycling stability.Needle-like NC layer coated on the yolk-shell structure of CoS2 effectively lowers the charge transfer resistance to obtain ex-traordinary ORR/OER activities.It indicates that the integration of highly-conductive carbon onto pyrite-type sulfides is an effective strategy to acquire durable bifunctional ORR/OER catalysts.
基金项目
support by National Natural Science Foundation of China(52070074)
support by National Natural Science Foundation of China(21806031)
Outstanding Youth Fund of Heilongjiang Province(JQ2022E005)
LongJiang Scholars Program(Q201912)
Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(HC202144)
Graduate Student Innovation Research Projects of Heilongjiang University(YJSCX2022-219HLJU)
维普
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