人们越来越认识到，电化学界面的性质在提高析氢反应（HER）的性能方面发挥着越来越关键的作用。
该文中，研究人员首次使用Au/核-Ni(OH)2/壳纳米颗粒增强拉曼光谱提供了直接的动态光谱证据，证明了界面水分子和吸附的羟基物种（OHad）之间的相互作用对Ni(OH)2的HER性能的影响。值得注意的是，研究结果表明，OHad和界面水分子之间的相互作用促进了弱氢键水的形成，促进了有利于提高HER性能的环境。
此外，观察到的Au@2nm Ni(OH)2去质子化步骤证实了OHad参与反应。通过拉曼和X射线光电子能谱证实了Ni(OH)2向NiO相变这一现象。水分子在相变过程中OH拉伸频率的显著红移证实了表面OHad破坏了界面水分子的氢键网络。通过操纵的外壳厚度Au@Ni(OH)2，还验证了OHad和界面水分子之间的相互作用。
总之，研究结果强调了电化学界面工程作为提高电催化性能的有效方法的潜力。
附：英文原文
Title: In Situ Probing the Structure Change and Interaction of Interfacial Water and Hydroxyl Intermediates on Ni(OH)2 Surface over Water Splitting
Author: Huajie Ze, Zhi-Lan Yang, Mu-Lin Li, Xia-Guang Zhang, Yao-Lin A, Qing-Na Zheng, Yao-Hui Wang, Jing-Hua Tian, Yue-Jiao Zhang, Jian-Feng Li
Issue&Volume: April 24, 2024
Abstract: There is growing acknowledgment that the properties of the electrochemical interfaces play an increasingly pivotal role in improving the performance of the hydrogen evolution reaction (HER). Here, we present, for the first time, direct dynamic spectral evidence illustrating the impact of the interaction between interfacial water molecules and adsorbed hydroxyl species (OHad) on the HER properties of Ni(OH)2 using Au/core-Ni(OH)2/shell nanoparticle-enhanced Raman spectroscopy. Notably, our findings highlight that the interaction between OHad and interfacial water molecules promotes the formation of weakly hydrogen-bonded water, fostering an environment conducive to improving the HER performance. Furthermore, the participation of OHad in the reaction is substantiated by the observed deprotonation step of Au@2 nm Ni(OH)2 during the HER process. This phenomenon is corroborated by the phase transition of Ni(OH)2 to NiO, as verified through Raman and X-ray photoelectron spectroscopy. The significant redshift in the OH-stretching frequency of water molecules during the phase transition confirms that surface OHad disrupts the hydrogen-bond network of interfacial water molecules. Through manipulation of the shell thickness of Au@Ni(OH)2, we additionally validate the interaction between OHad and interfacial water molecules. In summary, our insights emphasize the potential of electrochemical interfacial engineering as a potent approach to enhance electrocatalytic performance.
DOI: 10.1021/jacs.4c00948
