A tailored double perovskite nanofiber catalyst enables ultrafast oxygen evolution.
A tailored double perovskite nanofiber catalyst enables ultrafast oxygen evolution.
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DOI：
10.1038/ncomms14586
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发表时间：
2017-02-27
影响因子：
16.6
通讯作者：
Liu M
中科院分区：
文献类型：
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作者：
Zhao B;Zhang L;Zhen D;Yoo S;Ding Y;Chen D;Chen Y;Zhang Q;Doyle B;Xiong X;Liu M
可充电金属-空气电池和水分解是未来可持续能源的极具竞争力的选择，但由于缺乏成本效益高、高效和稳定的析氧反应催化剂，它们的商业化受到阻碍。本文报道了合理设计和合成的双钙钛矿型PrBa0.5Sr0.5Co1.5Fe0.5O5+δ纳米纤维作为高效、稳健的析氧反应催化剂。经电化学测量和第一性原理计算证实，在PrBaCo2O5+δ中共掺杂锶和铁可以非常有效地提高本构活性（几何表面积归一化，约4.7倍）。此外，当直径减小到~ 20nm时，纳米纤维形态显著提高了其质量活性（提高了~ 20倍），这归因于增加的表面积和意想不到的内在活性增强，这可能是由于与部分表面还原相关的有利的eg电子填充，正如化学滴定和电子能量损失谱所揭示的那样。高效稳定的析氧催化剂的设计对水裂解和金属-空气电池技术具有重要意义。在此，作者制备了双钙钛矿纳米纤维，并证明了共掺杂和纳米结构对析氧性能的有利影响。
Rechargeable metal–air batteries and water splitting are highly competitive options for a sustainable energy future, but their commercialization is hindered by the absence of cost-effective, highly efficient and stable catalysts for the oxygen evolution reaction. Here we report the rational design and synthesis of a double perovskite PrBa0.5Sr0.5Co1.5Fe0.5O5+δ nanofiber as a highly efficient and robust catalyst for the oxygen evolution reaction. Co-doping of strontium and iron into PrBaCo2O5+δ is found to be very effective in enhancing intrinsic activity (normalized by the geometrical surface area, ∼4.7 times), as validated by electrochemical measurements and first-principles calculations. Further, the nanofiber morphology enhances its mass activity remarkably (by ∼20 times) as the diameter is reduced to ∼20 nm, attributed to the increased surface area and an unexpected intrinsic activity enhancement due possibly to a favourable eg electron filling associated with partial surface reduction, as unravelled from chemical titration and electron energy-loss spectroscopy. The design of efficient and stable oxygen evolution catalysts has implications for water splitting and metal-air battery technology. Here, the authors fabricate double perovskite nanofibers and demonstrate the favourable effects of co-doping and nanostructuring on oxygen evolution performance.