The critical role of A, B-site cations and oxygen vacancies on the OER electrocatalytic performances of Bi0.15Sr0.85Co1-Fe O3-δ (0.2 ≤ x ≤ 1) perovskites in alkaline media
The critical role of A, B-site cations and oxygen vacancies on the OER electrocatalytic performances of Bi0.15Sr0.85Co1-Fe O3-δ (0.2 ≤ x ≤ 1) perovskites in alkaline media
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DOI：
10.1016/j.cej.2022.138646
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发表时间：
2022-08
影响因子：
15.1
通讯作者：
Jing Li;F. Yang;Yunzhu Du;Min Jiang;Xi Cai;Q. Hu;Junliang Zhang
中科院分区：
文献类型：
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作者：
Jing Li;F. Yang;Yunzhu Du;Min Jiang;Xi Cai;Q. Hu;Junliang Zhang
开发高活性、高耐久性和低成本的钙钛矿型电催化剂为促进清洁能源技术的商业化提供了一个有前途的解决方案。本文采用传统固相反应法制备了Bi0.15Sr0.85Co1− xFexO 3 −δ（x= 0.2，0.4，0.6，0.8，1）钙钛矿材料，并研究了其在0.1M KOH溶液中的OER电催化活性和耐久性，以揭示A、B位阳离子和氧空位的关键作用。结果表明，OER活性随x的增加而降低.结果表明，BiSC 0.8F 0.2具有较低的过电位（10 mA/cm 2时，旋转圆盘电极上为330 mV，碳纸电极上为283 mV）和良好的长期稳定性，在167.5 h内过电位仅增加了17 mV。通过对体相和表面性质的综合分析和讨论，揭示了A、B位阳离子和氧空位对OER的关键作用，并建立了Co2+含量、氧非化学计量比和OER过电位之间的关系。最重要的是，在合成的钙钛矿上发现了高度A位缺陷的表面层，这通过暴露更多活性B位阳离子来促进OER。本工作不仅报道了一种具有高活性和上级耐久性的有前途的OER电催化剂，而且还提供了利用固态反应法进行高效和稳定的钙钛矿OER电催化剂的相关设计的前景。
Development of perovskite-type electrocatalysts with high activity, excellent durability and affordable cost provides a promising solution to promote commercialization of clean energy technologies. Here we prepared Bi0.15Sr0.85Co1−xFexO3−δ(x= 0.2, 0.4, 0.6, 0.8, 1) perovskites by the conventional solid-state reaction route, and investigated their OER electrocatalytic activity and durability in 0.1 M KOH solution to reveal the critical role of A, B-site cations and oxygen vacancies. Results show the OER activity decreases with increasingx. The optimum composition, BiSC0.8F0.2, presents impressive electrocatalytic performances with low overpotential (330 mV on rotation disk electrode, and 283 mV on carbon paper electrode at 10 mA/cm2) and excellent long-time durability showing a small increase in the overpotential of 17 mV in 167.5 h. Comprehensive analysis and discussion on the bulk and surface properties reveal the critical role of A, B-site cations and oxygen vacancies on OER, and interrelations of Co2+fraction, oxygen non-stoichiometry and the OER overpotential have been established. Most importantly, a highly A-site deficient surface layer is found on the as-synthesized perovskite, which facilitate OER by exposing more active B-site cations. This work not only reports a promising OER electrocatalyst with high activity and superior durability, but also provides perspectives on relational design for highly efficient and stable perovskite electrocatalysts for OER using solid-state reaction method.