Hou Dewen, He Haiying, Agyapong-Fordjour Frederick, Xie Zhenhua, Kang Sinwoo, Priyadarsini Adyasa, Kattel Shyam, Lopes Pietro Papa, Zapol Peter, Liu Yuzi, Li Gengnan
Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Department of Physics and Astronomy, Valparaiso University, Valparaiso, Indiana 46383, United States.
ACS Appl Mater Interfaces. 2025 Jul 16;17(28):41271-41281. doi: 10.1021/acsami.5c06555. Epub 2025 Jun 30.
Understanding the interaction between ions in the electrolyte and electrode materials plays an important role in optimizing the water electrolysis performance for hydrogen production. Herein, the synergistic effect of iron (Fe) in the electrolyte and interlayer anions within the layered structure on the oxygen evolution reaction (OER) has been investigated by combining material synthesis with controlled structure, multiple characterization techniques, and first-principles calculations. Nickel aluminum layered double hydroxides (NiAl-LDHs) with different interlayer anions (CO, Cl, and Br) show similar oxygen evolution activity in the absence of Fe species in the electrolyte. The addition of Fe into the electrolyte results in improved performance for all of the NiAl-LDHs, following the rank LDH-Br > LDH-Cl > LDH-CO, under all of the conditions with varied concentration of Fe. X-ray absorption spectroscopy and identical location electron microscopy analyses show that the LDH structure remains unchanged after the OER activity test, while in situ stationary probe rotating disk electrode inductively coupled plasma mass spectrometry (SPRDE-ICP-MS) measurements show partial dissolution of the intercalating halide ions during cycling, with less dissolution for Br-intercalated materials. Insights from theoretical calculations demonstrate the thermodynamic preference of Br to remain intercalated in the presence of Fe, while the stronger adsorption of Fe(OH) species on the LDH-Br sample promotes the OER activity. These results provide mechanistic insights into the rational design of active layered materials with an enhanced OER performance for efficient water electrolysis.
了解电解质中的离子与电极材料之间的相互作用对于优化水电解制氢性能起着重要作用。在此，通过将材料合成与可控结构、多种表征技术以及第一性原理计算相结合，研究了电解质中的铁（Fe）与层状结构中的层间阴离子对析氧反应（OER）的协同作用。在电解质中不存在铁物种的情况下，具有不同层间阴离子（CO、Cl和Br）的镍铝层状双氢氧化物（NiAl-LDHs）表现出相似的析氧活性。在所有铁浓度不同的条件下，向电解质中添加铁均能提高所有NiAl-LDHs的性能，顺序为LDH-Br > LDH-Cl > LDH-CO。X射线吸收光谱和同位电子显微镜分析表明，OER活性测试后LDH结构保持不变，而原位固定探针旋转圆盘电极电感耦合等离子体质谱（SPRDE-ICP-MS）测量表明，循环过程中层间卤离子会部分溶解，Br插层材料的溶解较少。理论计算结果表明，在有铁存在的情况下，Br更倾向于保持插层状态，而Fe(OH)物种在LDH-Br样品上的更强吸附促进了OER活性。这些结果为合理设计具有增强OER性能的活性层状材料以实现高效水电解提供了机理见解。
