Activating the oxygen electrocatalytic activity of layer-structured Ca 0.5 CoO 2 nanofibers by iron doping
Activating the oxygen electrocatalytic activity of layer-structured Ca 0.5 CoO 2 nanofibers by iron doping
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铁掺杂激活层状结构Ca 0.5 CoO 2 纳米纤维的氧电催化活性
DOI：
10.1039/d1dt03883d
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发表时间：
2022
影响因子：
4
通讯作者：
Liu, Meilin
中科院分区：
文献类型：
--
作者：
Li, Mingyu;Zhao, Bote;Zhao, Yun;Chen, Yu;Liu, Meilin
开发低成本、高效、稳定的析氧反应（OER）电催化剂对于许多有前景的能量存储和转换应用（包括金属-空气电池和水裂解技术）具有重要意义。在这里，我们报告了一个层结构的Ca0.5CoO2纳米纤维组成的互连的纳米片，使用静电纺丝工艺合成。Ca0.5CoO2的OER活性可以通过铁掺杂显著提高，Ca0.5Co1− xFexO 2（x = 0.25）在10 mA cm−2电流密度下的过电位仅为346 mV。在1.6 V时，Ca 0.5Co 0.75 Fe 0.25 O2的质量活度和本征活度分别是Ca 0.5CoO2的18.7倍和11.4倍。铁掺杂改变了Ca0.5CoO2的电子结构，导致表面钴的部分氧化和高氧化性物质（O22−/O2）的增加。因此，具有调谐电子状态的Ca0.5Co0.75Fe0.25O2纳米纤维显示出作为OER的成本效益和高效的电催化剂的巨大潜力。
The development of low-cost, highly efficient and stable electrocatalysts for the oxygen evolution reaction (OER) is of great significance for many promising energy storage and conversion applications, including metal–air batteries and water splitting technology. Here we report a layer-structured Ca0.5CoO2 nanofibers composed of interconnected ultrathin nanoplates, synthesized using an electrospinning process. The OER activity of Ca0.5CoO2 can be dramatically improved by iron doping, and the overpotential of Ca0.5Co1−xFexO2 (x = 0.25) is only 346 mV at a current density of 10 mA cm−2. The mass activity and intrinsic activity of Ca0.5Co0.75Fe0.25O2 at 1.6 V are, respectively, ∼18.7 and ∼11.4 times higher than those of Ca0.5CoO2. Iron doping modifies the electronic structure of Ca0.5CoO2, resulting in partial oxidation of the surface cobalt and increased amount of highly oxidative species (O22−/O2). Consequently, Ca0.5Co0.75Fe0.25O2 nanofibers with tuned electronic states have shown great potential as cost-effective and efficient electrocatalysts for OER.