Prior studies have demonstrated that Ruddlesden–Popper (RP) type perovskite oxides exhibit promising electrocatalytic properties for oxygen evolution reaction (OER). However, the limited electrocatalytic activity has impeded their widespread utilization. The incorporation of heteroatoms into the Ruddlesden–Popper type structure has been identified as an effective strategy to enhance the electrocatalytic performance. This research presents the systematic design and synthesis of RP type perovskite oxide LaSrFeO4 (LSFO), followed by the optimization of electrocatalytic activity through Ni substitution at the Fe site of SLFO to create LaSrFe1-xNixO4 (LSFNO-x, x = 0.2, 0.4, and 0.5). Therein, the LSFNO-0.4 sample achieved a current density of 10 mA·cm−2 with an overpotential of only 340 mV. Additionally, it displayed exceptional stability over 120 h in a 1.0 M KOH solution. Both experimental and theoretical studies suggest that the addition of Ni cation increases the Fe − O covalency, and impacts the morphology and surface electron density of LSFO. This substitution results in a greater electrochemically active surface area, improved electron transfer, and optimization of hydrogen/water absorption free energy. This study presents a successful approach for enhancing the OER performance of Ruddlesden–Popper LSFO through the deliberate control of Fe − O covalent bonding.

中文翻译：

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通过杂原子掺入增强Ruddlesden-Popper钙钛矿氧化物的析氧反应性能


先前的研究表明，Ruddlesden-Popper (RP) 型钙钛矿氧化物在析氧反应 (OER) 中表现出有前景的电催化性能。然而，有限的电催化活性阻碍了它们的广泛应用。将杂原子掺入 Ruddlesden-Popper 型结构已被认为是增强电催化性能的有效策略。本研究提出了RP型钙钛矿氧化物LaSrFeO4（LSFO）的系统设计和合成，然后通过在SLFO的Fe位点进行Ni取代来优化电催化活性，以产生LaSrFe1-xNixO4（LSFNO-x，x = 0.2，0.4，和0.5）。其中，LSFNO-0.4样品实现了10 mA·cm−2的电流密度，过电势仅为340 mV。此外，它在 1.0 M KOH 溶液中在 120 小时内表现出卓越的稳定性。实验和理论研究表明，Ni 阳离子的添加​​增加了 Fe - O 共价键，并影响 LSFO 的形貌和表面电子密度。这种替代导致更大的电化学活性表面积、改善的电子转移以及氢/水吸收自由能的优化。这项研究提出了一种通过刻意控制 Fe-O 共价键来提高 Ruddlesden-Popper LSFO 的 OER 性能的成功方法。