Effects of Electrochemical Conditioning on Nickel-Based Oxygen Evolution Electrocatalysts
Effects of Electrochemical Conditioning on Nickel-Based Oxygen Evolution Electrocatalysts
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DOI：
10.1021/acscatal.2c01001
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发表时间：
2022-08
期刊：
影响因子：
12.9
通讯作者：
Yoon Jun Son;Seonwoo Kim;V. Leung;Kenta Kawashima;Jungchul Noh;Kihoon Kim;Raúl A. Márquez;Omar A
中科院分区：
文献类型：
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作者：
Yoon Jun Son;Seonwoo Kim;V. Leung;Kenta Kawashima;Jungchul Noh;Kihoon Kim;Raúl A. Márquez;Omar A
通过计时电位法 (CP) 和循环伏安法 (CV) 进行电化学调节对于析氧反应 (OER) 电催化剂的活化至关重要。虽然许多报告使用 CP 或 CV 激活 OER 电催化剂，但这两种用于激活 OER 电催化材料的电化学调节方法之间的固有差异仍有待探索。在这里，我们采用（ⅰ）Ni箔、（ⅱ）氟掺杂氧化锡玻璃基底上不同厚度的NiSe预催化剂薄膜和（ⅲ）Ni箔基底上的NiSe预催化剂薄膜，研究了在Fe纯化和Fe未纯化KOH电解液中CP和CV电化学调节对Ni基OER预催化剂和基底的影响。研究发现，与 CP 电化学调节相比，CV 电化学调节可以导致镍基预催化剂和基材更高程度的原位氧化和 Fe 掺入。反过来，这又带来了镍基电催化剂不同的材料特性（例如，原位氧化层厚度、组成、结晶度和形态）和电化学特性（例如，活性表面积、电子传输限制和本征活性），从而不仅影响其OER活性，而且使OER活性起源的解释复杂化。本研究确定了 CP 和 CV 电化学调理对镍基 OER 电催化剂的不同影响，并深入了解电化学调理方法的选择，以更好地研究 OER 电催化剂。总的来说，这些结果表明 NiO x H y 材料特性和电化学在确定 Fe 掺入 H y 层的程度方面发挥着关键作用。
Electrochemical conditioning via chronopotentiometry (CP) and cyclic voltammetry (CV) is essential for the activation of oxygen evolution reaction (OER) electrocatalysts. While many reports have activated OER electrocatalysts using either CP or CV, the inherent differences between these two electrochemical conditioning methods for the activation of OER electrocatalytic materials have yet to be explored. Here, we investigate the effects of CP and CV electrochemical conditioning on a Ni-based OER precatalyst and substrate in Fe-purified and Fe-unpurified KOH electrolytes by employing (ⅰ) Ni foil, (ⅱ) NiSe precatalyst films with different thicknesses on the fluorine-doped tin oxide glass substrate, and (ⅲ) NiSe precatalyst films on Ni foil substrates. It was found that CV electrochemical conditioning can result in a higher degree of in situ oxidation and Fe incorporation for Ni-based precatalysts and substrates compared to CP electrochemical conditioning. In turn, this brought about different material properties ( e.g. , in situ oxidized layer thickness, composition, crystallinity, and morphology) and electrochemical characteristics ( e.g. , active surface area, electron transport limitation, and intrinsic activity) of Ni-based electrocatalysts, thereby not only affecting their OER activity but also complicating the interpretation of the origin of OER activity. This study identifies the distinct effects of CP and CV electrochemical conditioning on Ni-based OER electrocatalysts and provides insight into the choice of the electrochemical conditioning method to better investigate OER electrocatalysts. Collectively, these results suggest that both NiO x H y material properties and the electrochemical can play a key role in determining the degree of Fe incorporation into the H y layer.