Oxygen Evolution Electrocatalysis of a Single MOF-Derived Composite Nanoparticle on the Tip of a Nanoelectrode
Oxygen Evolution Electrocatalysis of a Single MOF-Derived Composite Nanoparticle on the Tip of a Nanoelectrode
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DOI：
10.1002/anie.201903283
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发表时间：
2019-06-24
影响因子：
16.6
通讯作者：
Schuhmann, Wolfgang
中科院分区：
文献类型：
--
作者：
Aiyappa, Harshitha Barike;Wilde, Patrick;Schuhmann, Wolfgang
利用大电极技术测定纳米材料的本征电催化活性会受到系综效应和薄膜效应的影响。在这里，一种独特的颗粒挂棒方法被用来在纳米电极表面生长单一的金属-有机骨架(MOF；ZIF-67)纳米颗粒，该纳米颗粒被热解生成钴/氮掺杂碳(CON/C)复合纳米颗粒，该纳米颗粒对析氧反应(OER)表现出非常高的催化活性，在1.77V(vs.RHE)下的电流密度高达230mAcm(-2)，在540 mV过电位下的高周转频率(TOF)为29.7s(-1)。同位透射电子显微镜(IL-TEM)分析证实了MOF的自牺牲模板性质，而后电催化研究表明，在OER过程中，Co中心在CON/C复合材料中聚集。单一实体的电化学分析可以推导出固有的电催化活性，并提供对电催化剂在反应条件下的瞬时行为的洞察。
Determination of the intrinsic electrocatalytic activity of nanomaterials by means of macroelectrode techniques is compromised by ensemble and film effects. Here, a unique particle on a stick approach is used to grow a single metal-organic framework (MOF; ZIF-67) nanoparticle on a nanoelectrode surface which is pyrolyzed to generate a cobalt/nitrogen-doped carbon (CoN/C) composite nanoparticle that exhibits very high catalytic activity towards the oxygen evolution reaction (OER) with a current density of up to 230mAcm(-2) at 1.77V (vs. RHE), and a high turnover frequency (TOF) of 29.7s(-1) at 540mV overpotential. Identical location transmission electron microscopy (IL-TEM) analysis substantiates the self-sacrificial template nature of the MOF, while post-electrocatalysis studies reveal agglomeration of Co centers within the CoN/C composite during the OER. Single-entity electrochemical analysis allows for deriving the intrinsic electrocatalytic activity and furnishes insight into the transient behavior of the electrocatalyst under reaction conditions.