Designing N-doped carbon nanotubes and Fe-Fe3C nanostructures co-embedded in B-doped mesoporous carbon as an enduring cathode electrocatalyst for metal-air batteries
Designing N-doped carbon nanotubes and Fe-Fe3C nanostructures co-embedded in B-doped mesoporous carbon as an enduring cathode electrocatalyst for metal-air batteries
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DOI：
10.1039/c7ta04597b
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发表时间：
2017-08-28
影响因子：
11.9
通讯作者：
Nanda, K. K.
中科院分区：
文献类型：
--
作者：
Nandan, Ravi;Nanda, K. K.
氧还原和析氧反应在电化学转化/储存装置如再生/醇/氢基燃料电池和金属-空气电池中是极其重要的。本论文采用一种简单合理的合成方法，将N掺杂碳纳米管（N-CNTs）和Fe-Fe_3C纳米结构共嵌入B掺杂介孔碳纳米结构（BFNCNTs）中，制备了一种无贵金属的上级双功能析氧/还原电催化剂。N和B的结合与可忽略/不可检测的B-N形成和Fe-Fe 3 C纳米结构通过引入大量缺陷、局部异质性和高比表面积（类似于272 m（2）g（-1））而导致上级性能。此外，介孔硼掺杂碳作为NCNTs和Fe-Fe 3C的主体材料，它提供了良好的连接性以及持久催化的保护涂层。值得注意的是，在加速稳定性测试和ORR的燃料耐受性下，具有更多的正起始（-30 mV）和半波电位（-225 mV）以及-94%的电流保持率，结合较低的起始电位（422 mV）和E-j=10（OER）（562 mV）电位以及高电流密度（190 mA cm（-2）@0.8 V vs. Ag/AgCl）的OER，表明BFNCNT具有上级双功能行为。BFNCNT的完全氧电化学活性Δ E = E-j（OER）=10 = E-1/2（ORR）= 0.788 V低于最近报道的各种现有技术的双功能催化剂。此外，使用BFNCNTs作为驱动发光二极管的阴极电极的原型电池制造已被证明。总体而言，BFNCNT具有用作电化学能量装置的非贵重电催化剂的潜力。
Oxygen reduction and evolution reactions are of immense importance in electrochemical conversion/ storage devices like regenerative/alcohol/hydrogen based fuel cells and metal-air batteries. Here, a rational facile synthesis methodology has been developed to design N-doped carbon nanotubes (N-CNTs) and Fe-Fe3C nanostructures co-embedded in B-doped mesoporous carbon nanostructures (BFNCNTs) as a noble metal-free superior bi-functional electrocatalyst for oxygen evolution/reduction reactions. The incorporation of N and B with negligible/undetectable B-N formation and Fe-Fe3C nanostructures leads to the superior performance by introducing plenty of defects, local heterogeneity and a high specific surface area (similar to 272 m(2) g(-1)). Besides, mesoporous boron-doped carbon acts as a host material for NCNTs and Fe-Fe3C, and it offers good connectivity as well as a protective coating for durable catalysis. Remarkably, more positive onset (-30 mV) and half-wave potentials (-225 mV) with -94% current retention under accelerated stability test and fuel tolerance for the ORR, in combination with lower onset (422 mV) and E-j=10(OER) (562 mV) potentials with high current density (190 mA cm(-2) @ 0.8 V vs. Ag/AgCl) for the OER as compared to commercial state-of-the-art electrocatalysts suggest superior bifunctional behavior of BFNCNTs. The complete oxygen electrochemical activity Delta E = E-j(OER)=10 = E-1/2(ORR) = 0.788 V for BFNCNTs is lower than recently reported various state-of-the-art bifunctional catalysts. Besides, a prototype battery fabrication using BFNCNTs as the cathode electrode for driving a light emitting diode has been demonstrated. Overall, BFNCNTs have potential to serve as a non-precious electrocatalyst for electrochemical energy devices.