氮掺杂的类石墨烯纳米片的制备及其在锌-空气电池中的应用（英文）

采用一种简单方法制备具有优异氧还原反应(ORR)活性的、无金属的氮掺杂碳材料。以双氰胺(DCD)为氮源,蔗糖、β-环糊精和壳聚糖为不同的碳源,通过简单的热解法制备出氮掺杂的类石墨烯纳米片催化剂CN-nanosh(suc)、CN-nanosh(cyc)和CN-nanosh(ch)。这些催化剂在碱性溶液中表现出优异的ORR活性,以CN-nanosh(suc)为阴极催化剂的锌-空气电池具有201.33m W·cm~(-2)的最大功率密度,在100 mA·cm~(-2)的大电流密度下能持续放电50多小时,电池性能接近目前报道的无金属阴极催化剂锌-空气电池的最好性能。     

MnO/氮掺杂石墨烯复合正极材料在锂空气电池中的高效催化性能研究

本文采用水热法制备了MnO/氮掺杂石墨烯复合材料.作为非水锂空气电池的正极催化剂,该复合材料表现出了优异的电化学性能以及循环稳定性.在充放电电流密度为0.05 mA cm~(-2)时,其能量效率高达84.6%,远高于目前文献所报道的非贵金属催化剂的能量效率,也超过了基于贵金属的催化剂.其氧还原反应(ORR)和氧析出反应(OER)的过电势分别仅为0.11和0.41 V.扫描电子显微镜(SEM)和透射电子显微镜(TEM)结果表明,所制备的MnO纳米颗粒能够均匀地分散在氮掺杂石墨烯的表面.密度泛函理论(DFT)计算揭示,MnO(100)面是主要的催化活性面,其理论ORR和OER的过电势分别仅为0.21与0.24 V,充放电电势差为0.45V,与实验结果0.52 V相当.     

基于金属有机框架衍生的Fe-N-C纳米复合材料作为高效的氧还原催化剂（英文）

开发用于氧还原反应(ORR)的低成本和高性能的非贵金属催化剂(NPMC)对于燃料电池的商业化至关重要。在这里,我们介绍了一种简单合成的由Fe3C纳米粒子包裹在介孔N掺杂碳(Fe-NC)中的NPMC材料,包括MIL-100(Fe)与葡萄糖和尿素的物理混合,以及随后在惰性气体下的热解。由此获得的Fe-N-C-900 (在900°C下制备的材料)表现出优异的电催化活性,高耐久性和对ORR卓越的甲醇耐受性,其催化性能与商业Pt/C在碱性介质中的催化性能相当。Fe-N-C-900在ORR中表现出优异的催化活性和稳定性,这是由于其较大的BET比表面积,较大的孔体积,氮掺杂剂,活性Fe3C纳米粒子以及其中活性官能团之间的协同效应。     

静电纺丝辅助后处理合成钴氮共掺杂碳纤维用于氧还原催化剂

通过静电纺丝辅助后处理策略开发了Co和N掺杂碳纳米纤维(N-Co@CNFs)的高效ORR催化剂.该方法可以有效提高氮的掺杂水平,优化氮掺杂位的状态,生成高活性的石墨氮主导位点,提高碳纳米纤维骨架的石墨化程度.同时,在一维碳纳米纤维的独特高度开放的骨架上实现高活性的氮掺杂位点和钴基位点合理整合.这种独特的纳米结构使得制备的N-Co@CNF具有优异的电催化活性、四电子选择性和在碱性电解质中的稳定性.     

一步热解核黄素制备高性能氧还原反应电催化剂

质子交换膜燃料电池具有零污染、能量密度高、操作温度低和超静低音等优点,因而广泛应用于新能源汽车动力电源.然而质子交换膜燃料电池阴极氧还原反应(ORR)过程缓慢且复杂,因此需要大量的高性能ORR电催化剂.商品铂基催化剂是目前最为广泛使用的ORR催化剂,然而其高昂的价格阻碍了燃料电池汽车的商业化进程.因此,近年来人们致力于研发高性能的非贵金属ORR催化剂,并成功获得了具有高ORR活性及优异稳定性的催化剂.然而开发贵金属替代催化剂还存在制备过程较为复杂、单体有毒等缺点.核黄素具有成本低廉、无毒、氮含量高等优点,本文将其直接作为碳源和氮源,以无水氯化铁为铁前驱体,通过简单的一步热解法制备了高性能的Fe-N-C催化剂.表征结果表明,合成的催化剂表面由于氮的掺杂导致石墨烯存在较多的缺陷,其比表面积为301 m2 g-1且孔径分布主要位于45 nm处;催化剂由很薄、卷曲的石墨烯片层和一些颗粒组成,其中的碳材料高度石墨化且存在Fe2O3晶体.结合X射线光电子能谱和催化剂的ORR活性,推导出石墨化氮为ORR的主要活性位,铁在ORR反应中也起着重要作用.在氧气饱和的0.1 mol L-1 KOH溶液中,Fe-N-C催化剂的ORR活性达到4.16 mA cm-2,与商品Pt/C催化剂相当(4.46 mA cm-2).采用计时电流法在0.66 V(相对于RHE电位)下运行3 h后,Fe-N-C催化剂电流仅下降了3%,而Pt/C催化剂下降了40%,表明Fe-N-C催化剂与Pt/C催化剂具有相近的ORR活性,但稳定性比Pt/C催化剂更出色.测试结果表明,Fe-N-C催化剂的抗甲醇毒化性能远优于Pt/C催化剂.在酸性介质中,Fe-N-C催化剂的ORR活性比Pt/C催化剂低,但稳定性更高.总之,该Fe-N-C催化剂在碱性介质中有较高的活性和稳定性,在酸性介质中有较高的稳定性.因此,我们采用廉价、无毒的核黄素作为碳氮源,通过简单的一步热解法制备出的Fe-N-C催化剂能较好地满足燃料电池ORR催化剂高性能和低成本的要求,具有很好的应用前景.     

负载酞菁铁的氮掺杂中空碳球的电催化氧还原性能（英文）

开发低成本、高性能的氧还原反应（ORR）催化剂是当前的研究热点.虽然酞菁铁（FePc）在几十年前就被证明能高效地电催化氧还原反应,但由于其电子传导性和稳定性较差,无法取代商用的Pt/C催化剂.氮掺杂碳材料不仅化学性质稳定、电子传导性好,还有一定的氧还原催化活性.本文首先制备了聚苯乙烯@聚多巴胺球前驱体,经过高温碳化后制得了氮掺杂中空碳球,进而负载酞菁铁后制备了负载酞菁铁的氮掺杂中空碳球复合材料（FePc-NHCS）.通过调整煅烧温度和酞菁铁的负载量,可进一步调控FePc-NHCS的多孔结构、石墨化程度、氮掺杂的种类与含量及酞菁铁的负载状态.优化后的FePc-NHCS在碱性电解质中显示出优异的ORR催化活性,其半波电位和稳定性均高于商用Pt/C催化剂.研究结果表明,掺杂与复合是增强单项催化组分活性的有效途径.此外,通过调控催化剂的结构和组分也能有效地优化催化剂的氧化还原性能.     

高分散钴氮共掺杂碳纳米纤维氧还原催化剂

过渡金属氮掺杂碳基催化剂已成为替代铂基氧还原反应(ORR)电催化剂的理想选择。本文通过静电纺丝技术制备了高比表面、高度分散的钴原子配位氮掺杂的碳纳米纤维催化剂(Co-N/C)。X射线衍射(XRD)和高分辨率透射电镜(HRTEM)结果证实Co元素高度分散于制备的Co-N/C催化剂中。X射线光电子能谱结果表明N元素主要以吡啶N和石墨N形式存在。该Co-N/C催化剂对ORR反应呈现出较高的电催化活性,其氧还原起始和半波电位分别为0.92 V和0.80 V(相对于标准氢电极),接近于商业化Pt/C催化剂的性能。以制备的Co-N/C催化剂作为阴极,25℃下锌空气燃料电池的开路电位1.54 V、最大功率密度达到了190 m V·cm~(-2)表明该催化剂具有良好的应用前景。     

一步热解核黄素制备高性能氧还原反应电催化剂（英文）

质子交换膜燃料电池具有零污染、能量密度高、操作温度低和超静低音等优点,因而广泛应用于新能源汽车动力电源.然而质子交换膜燃料电池阴极氧还原反应(ORR)过程缓慢且复杂,因此需要大量的高性能ORR电催化剂.商品铂基催化剂是目前最为广泛使用的ORR催化剂,然而其高昂的价格阻碍了燃料电池汽车的商业化进程.因此,近年来人们致力于研发高性能的非贵金属ORR催化剂,并成功获得了具有高ORR活性及优异稳定性的催化剂.然而开发贵金属替代催化剂还存在制备过程较为复杂、单体有毒等缺点.核黄素具有成本低廉、无毒、氮含量高等优点,本文将其直接作为碳源和氮源,以无水氯化铁为铁前驱体,通过简单的一步热解法制备了高性能的Fe–N–C催化剂.表征结果表明,合成的催化剂表面由于氮的掺杂导致石墨烯存在较多的缺陷,其比表面积为301 m~2g~(–1)且孔径分布主要位于45 nm处;催化剂由很薄、卷曲的石墨烯片层和一些颗粒组成,其中的碳材料高度石墨化且存在Fe_2O_3晶体.结合X射线光电子能谱和催化剂的ORR活性,推导出石墨化氮为ORR的主要活性位,铁在ORR反应中也起着重要作用.在氧气饱和的0.1 mol L~(–1) KOH溶液中,Fe–N–C催化剂的ORR活性达到4.16 mA cm~(–2),与商品Pt/C催化剂相当(4.46 mA cm~(–2)).采用计时电流法在0.66 V(相对于RHE电位)下运行3 h后,Fe–N–C催化剂电流仅下降了3%,而Pt/C催化剂下降了40%,表明Fe–N–C催化剂与Pt/C催化剂具有相近的ORR活性,但稳定性比Pt/C催化剂更出色.测试结果表明,Fe–N–C催化剂的抗甲醇毒化性能远优于Pt/C催化剂.在酸性介质中,Fe–N–C催化剂的ORR活性比Pt/C催化剂低,但稳定性更高.总之,该Fe–N–C催化剂在碱性介质中有较高的活性和稳定性,在酸性介质中有较高的稳定性.因此,我们采用廉价、无毒的核黄素作为碳氮源,通过简单的一步热解法制备出的Fe–N–C催化剂能较好地满足燃料电池ORR催化剂高性能和低成本的要求,具有很好的应用前景.     

不同氮掺杂石墨烯氧还原反应活性的密度泛函理论研究

N掺杂石墨烯作为一种具有较高活性和稳定性的氧还原反应(ORR)催化剂,受到人们的广泛关注。然而不同的N掺杂类型对氧还原活性的影响一直存在争议。本文通过密度泛函理论分别对石墨型和吡啶型两种N掺杂石墨烯的ORR活性进行比较研究。能带结构分析表明,石墨氮掺杂石墨烯(GNG)的导电性随掺N量的增加而降低;吡啶氮掺杂石墨烯(PNG)的导电性则随掺N量的增加先提高后降低。当N掺杂浓度达到4.2%(原子分数)时,PNG具有最优导电性。且当N掺杂浓度大于1.4%时,PNG的导电率总是高于GNG。氧还原自由能阶梯曲线发现O₂的质子化是整个氧还原过程的潜在控制步骤。在同等氮掺杂浓度下,O₂的质子化自由能能变在GNG上低于在PNG上,意味着若在同等电子传输能力的情况下,GNG具有比PNG更优异的催化活性。进一步分析发现：当N掺杂浓度在低于2.8%时,GNG和PNG导电性差异小,其催化ORR活性由O₂质子化反应难易程度决定,GNG的催化活性优于PNG;当N掺杂浓度高于2.8%时,氮掺杂石墨烯的电子传输性能(导电性)成为决定催化剂ORR活性的主要因素,因此PNG表现出较GNG更高的活性。     

Fe-N共掺杂纳米碳材料的形貌对电化学还原反应的影响

众所周知,石墨烯片（GS）和碳纳米管是能源转化和储存应用中有效的催化剂. 然而,过渡金属基氮（N）掺杂的体系中经常形成GS和碳纳米管的复合物,使得该体系内的构效关系研究变得十分困难. 为了可控制备出含有理想物种的催化剂,作者尝试通过利用氮对碳纳米管生长的效应调节生成产物的形貌. 本文中,作者采用一步法制备了一系列Fe-N共掺杂的GS、GS/竹节碳纳米管(BCNTs)复合物及BCNTs催化剂. 为了评估碳形貌对催化剂性能的影响,作者采用氧气还原反应（ORR）及二氧化碳还原反应（CO₂RR）作为模型反应. 电化学测试结果表明,所有的样品当中仅含BCNTs的催化剂表现出最好的ORR活性（起始电位E_onset = 1.02 V_RHE）及CO₂RR活性（CO生成法拉第效率FE_CO = 91.1%,-0.6 V_RHE）. 进一步的研究表明,优异的活性与独特的BCNTs中存在的缺陷、较大的比表面积、高含量的吡啶N及FeN_x相关. 该工作加深了作者对形貌相关的ORR及CO₂RR过程的认识和理解.     

N,S-Co-Doped Porous Carbon Nanofiber Films Derived from Fullerenes (C60) as Efficient Electrocatalysts for Oxygen Reduction and a Zn–Air Battery

The development of highly efficient metal-free electrocatalysts for the oxygen reduction reaction (ORR) has attracted great attention for the creation of electrochemical energy devices. In this study, one-dimensional (1 D) fullerene nanofibers prepared from liquid–liquid interfacial precipitation are first fabricated into fullerene-derived carbon nanofiber films (FCNFs) through a simple filtration procedure. Then, pyrolysis of the FCNFs in the presence of ammonia and sulfur produces N- and S-co-doped porous carbon nanofiber films (N,S-PCNFs). As excellent metal-free electrocatalysts for the ORR, N,S-PCNFs exhibit remarkable catalytic activity, superior stability, and excellent methanol tolerance in both alkaline and acidic solution. Such a high ORR performance benefits from the robust porous nanofiber network structure with high concentrations of active N- and S- groups and abundant defects. Notably, upon practical use of N,S-PCNFs as catalysts in Zn-air batteries, a high power density and a large operating voltage are achieved, with a performance comparable to that of the commercial Pt/C catalyst. This work presents a facile strategy for the creation of a new class of energy nanomaterials based on fullerenes, demonstrating their practical uses in electrocatalytic ORR processes and Zn-air batteries.     

基于氮掺杂碳载铁复合物的锌空电池氧阴极催化剂

迫在眉睫的环境和能源问题推动人类探索可行、可靠和可再生的能源技术.锌-空气电池和氢氧燃料电池等器件显示出高能量转换效率,但是仍有许多难题有待克服,例如阴极侧上缓慢的氧还原反应(ORR),以及高昂的成本极大地限制了铂基催化剂在商业上的广泛应用.因此,开发高性能的廉价ORR催化剂具有重要意义.过渡金属碳氮化合物(M-N-C, M=Co, Fe等)成为最有希望替代铂基催化剂的一类材料, M-N-C催化剂可以通过直接热解含有过渡金属、氮和碳物种的前驱体合成.然而热解时金属原子易团聚,多孔结构不能被有效地控制,导致相对较差的催化活性.目前, MOF衍生的催化剂在能源转化和储存技术中得到了广泛的关注,其具有丰富的氮含量、高比表面积和可调的孔道结构等特点.本文报道了一种简便可靠可控的合成铁氮共掺杂碳十二面体纳米结构催化剂的方法,并作为阴极电催化剂用于锌空气电池中,测试结果证实,合成的铁氮共掺杂的纳米碳具有与铂基材料相当的活性和更加优异的稳定性.表面吸附了的邻菲罗啉铁的ZIF-8在碳化过程中,氮基团能够结合铁形成Fe Nx结构单元,因此可得到铁氮共掺杂的电催化剂.粉末X射线衍射,扫描电镜证实ZIF-8的成功合成.经过热解得到的催化剂中Fe Nx或Fe Cx衍射峰较弱,表明样品中铁含量较低,存在部分无定型铁.通过拉曼光谱分析发现,引入的邻菲罗啉在热解过程中诱导了缺陷的形成,所以Fe-NCDNA-0的ID/IG比值明显高于NC.同时ID/IG随着铁含量的增加而减少,这是因为铁可以诱导石墨化,诱导效应随着铁含量的增加而增加.分析氮气吸附-脱附等温线得出,引入邻菲罗啉之后,比表面积增加;而铁的引入因其占据了微孔结构,导致比表面积下降.同时电镜证实Fe-NCDNA-2具有较大的形貌扭曲,使得该材料具有较大的比表面积.系统的电化学研究表明,氮掺杂有利于增强ORR活性,在引入铁之后形成高效的活性中心会进一步提高催化性能.因此, Fe-NCDNA-2在碱性条件下表现出优异的ORR性能.线性扫描伏安法曲线表明,铁氮共掺杂的材料表现出与Pt/C相似的性能,其中Fe-NCDNA-2的半波电位(E1/2)为0.863 V,比商业Pt/C的电位更正(E1/2=0.841 V).同时, Fe-NCDNA-2具有更加优异的稳定性,测试30000 s后的电流保持率为80%(Pt/C:64%).在中性介质中,合成的材料也展示了较高的ORR活性.Fe-NCDNA-2的E1/2=0.715 V,催化30000 s后电流保持率77%,均优于商业Pt/C催化剂.组装的锌空气电池进一步验证其作为氧还原催化剂实际应用的可行性.相比于以Pt/C为催化剂做空气阴极的电池,以Fe-NCDNA-2组装的电池表现出更高的开路电压,更高的功率密度(184 m Wcm^-2),以及更加优异的充放电循环稳定性.该工作也有利于启发研究人员探索类似的氮掺杂过渡金属碳材料在各种催化上的应用.     

Red Bean Pod Derived Heterostructure Carbon Decorated with Hollow Mixed Transition Metals as a Bifunctional Catalyst in Zn-Air Batteries

Design and synthesis of low-cost and efficient bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in Zn-air batteries are essential and challenging. We report a facile method to synthesize heterostructure carbon consisting of graphitic and amorphous carbon derived from the agricultural waste of red bean pods. The heterostructure carbon possesses a large surface area of 625.5 m² g⁻¹, showing ORR onset potential of 0.89 V vs. RHE and OER overpotential of 470 mV at 5 mA cm⁻². Introducing hollow FeCo nanoparticles and nitrogen dopant improves the bifunctional catalytic activity of the carbon, delivering ORR onset potential of 0.93 V vs. RHE and OER overpotential of 360 mV. Electron energy-loss spectroscopy (EELS) O K-edge map suggests the presence of localized oxygen on the FeCo nanoparticles, suggesting the oxidation of the nanoparticles. Zn-air battery with these carbon-based catalysts exhibits a peak power density as high as 116.2 mW cm⁻² and stable cycling performance over 210 discharge/charge cycles. This work contributes to the advancement of bifunctional oxygen electrocatalysts while converting agricultural waste into value-added material.     

FeNi Nanoparticles Coated on N-doped Ultrathin Graphene-like Nanosheets as Stable Bifunctional Catalyst for Zn-Air Batteries

High-performance and low-cost bifunctional catalysts are crucial to energy conversion and storage devices. Herein, a novel oxygen electrode catalyst with high oxygen evolution reaction and oxygen reduction reaction (OER/ORR) performance is reported based on bimetal FeNi nanoparticles anchored on N-doped graphene-like carbon (FeNi/N−C). The complete 2D ultrathin carbon nanosheet is induced by etching and stripping of molten sodium chloride and its ions in the carbonization process at suitable temperature. The obtained FeNi/N−C catalyst exhibits rapid reaction kinetics for OER, efficient four electron transfer for ORR, and outstanding bifunctional performance with reversible oxygen electrode index of 0.87 V for OER/ORR. Zn-air batteries with a high open-circuit voltage of 1.46 V and a stable discharge voltage of 1.23 V are assembled using liquid electrolytes, zinc sheet as Zn-electrode and FeNi/N−C coating on carbon cloth as air-electrode. The specific capacity is as high as 816 mAh g⁻¹ and there is extremely little decay after charge-discharge cycle time of 275 h for the FeNi/N−C as oxygen electrode catalyst in Zn-air battery, which are much better than that assembled with Pt/C−RuO₂ catalyst.     

Continuous nitrogen-doped carbon nanotube matrix for boosting oxygen electrocatalysis in rechargeable Zn-air batteries

Developing robust oxygen electrocatalyst with high-performance is very significant for practical rechargeable Zn-air battery.We report herein the preparation of three-dimensional continuous nanocarbon network composed of interconnected nitrogen-doped carbon nanotubes and its application as oxygen electrocatalysis in rechargeable Zn-air battery.Except the excellent electrochemical bifunctionality,this carbon nanotube matrix also delivers an impressive battery performance.Specifically,an opencircuit voltage of 1.50 V as well as a high power density of 220 m W cm^-2 with remarkable cycling stability for 1600 h is achieved in the rechargeable Zn-air battery.The study not only provides an efficient bifunctional oxygen electrocatalyst but more importantly may pave significant concepts in designing robust electrode for long-life rechargeable Zn-air battery and other energy technologies.     

In situ confinement of iron-based active sites within high porosity carbon frameworks with enhanced activity for rechargeable Zn–air battery

Non-noble bifunctional electrocatalysts with robust activity and stability toward oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are greatly significant but challenging for Zn-air batteries. Here, in situ confinement of FeN_x active sites in high porosity carbon framework (FeN_x/CMCC) derived from chelate of carboxymethylcellulose (CMC) and iron ions were synthesized. Particularly, construction of FeN_x within porous carbon framework accelerates the electron transfer and the sufficient utilization of active centers, and then expedites the reaction kinetics of ORR and OER. As expected, the optimized FeN_x/CMCC exhibits superior ORR activity with a larger half-wave potential of 0.869 V. The rechargeable Zn-air battery delivers a higher power density of 99.6 mW/cm² and a special capacity of 781.9 mA h/g_Zn at 10 mA/cm², together with excellent durability of over 335 h. Remarkably, the as-assembled solid-state battery exhibits a higher open circuit voltage (OCV) of 1.5 V, a special capacity of 709.7 mA h/g_Zn, as well as prolonged cycling stability (90 h). Moreover, the flexible solid-state battery displays negligible loss of electrochemical performance under various bending angles, illustrating its potential application in flexible electronic devices.     

A facile template approach for the synthesis of mesoporous Fe3C/Fe-Ndoped carbon catalysts for efficient and durable oxygen reduction reaction

Layer-structured FeOCl was used as a novel inorganic template and the Fe doping source for the facile synthesis of three-dimensional polypyrrole structures which can be converted into mesoporous Fe₃C/Fe-N-doped carbon catalysts for efficient and robust oxygen reduction reaction.     

Mn-N-P doped carbon spheres as an efficient oxygen reduction catalyst for high performance Zn-Air batteries

Low-cost and efficient oxygen reduction reaction (ORR) electrocatalysts are the key to developing Zn-air batteries for renewable energy storage. Herein, the Mn-N-P doped carbon sphere was prepared through polymerization of hexachlorotripolyphosphazene (HCCP) and phloroglucinol, and then followed the calcination at 900 °C. Theory calculations demonstrated the introduction of Mn in N-P doped carbon could lower the dissociation barrier of O₂ into O* and promote the ORR through a 4e^? pathway. The as-prepared catalysts exhibited a half-wave potential of 0.82 V vs. RHE and limiting current density of 5.2 mA/cm² toward ORR, which was comparable to those of the commercial Pt/C catalysts. In addition, Zn-air batteries with 0.05 Mn-N-P-C catalysts showed a high specific capacity of 830 mAh/g_Zn and excellent cycle stability. This facile approach demonstrated herein could be a solution to develop optimum non-precious metal catalysts for the application in cathodes of proton exchange membrane fuel cells. This study also provides new insight to design the catalysts of multi-heteroatom coordinated metal in the carbon matrix for both fundamental researches and practical applications.     

Designed preparation of CoS/Co/MoC nanoparticles incorporated in N and S dual-doped porous carbon nanofibers for high-performance Zn-air batteries

The development of low-cost and highly efficient bifunctional electrocatalysts toward oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) is of critical importance for clean energy devices such as fuel cells and metal-air batteries.Herein,a sophisticated na nostructure composed of CoS,Co and MoC nanoparticles incorporated in N and S dual-doped porous carbon nanofibers(CoS/Co/MoC-N,SPCNFs) as a high-efficiency bifunctional electrocatalyst is designed and synthesized via an efficient multistep strategy.The as-prepared CoS/Co/MoC-N,S-PCNFs exhibit a positive half-wave potential(E_(1/2)) of0.871 V for ORR and a low overpotential of 289 mV at 10 mA/cm~2 for OER,outperforming the non-noble metal-based catalysts reported.Furthermore,the assembled Zn-air battery based on CoS/Co/MoC-N,SPCNFs delivers an excellent power density(169.1 mW/cm~2),a large specific capacity(819.3 mAh/g) and robust durability,demonstrating the great potential of the as-developed bifunctional electrocatalyst in practical applications.This work is expected to inspire the design of advanced bifunctional nonprecious metal-based electrocatalysts for energy storage.