In Situ Unraveling Surface Reconstruction of Ni‐ C o P Nanowire for Excellent Alkaline Water Electrolysis

作者：Haiquan Liu, Sihang Hu, Baojun Long, Huan Dai, Yafei Yang, Menghua Yang, Qi Zhang, Zunjian Ke, Wenqing Li, Dong He, Ziyu Wang, Xiangheng Xiao · 发表于：Energy & environment materials · 年份：2024 · DOI：10.1002/eem2.12834 · 被引用次数：13 · 研究领域：Electrocatalysts for Energy Conversion、Advanced battery technologies research、Fuel Cells and Related Materials

The surface reconstruction behavior of transition metal phosphides precursors is considered as an important method to prepare efficient oxygen evolution catalysts, but there are still significant challenges in guiding catalyst design at the atomic scale. Here, the CoP nanowire with excellent water splitting performance and stability is used as a catalytic model to study the reconstruction process. Obvious double redox signals and valence evolution behavior of the Co site are observed, corresponding to Co 2+ /Co 3+ and Co 3+ /Co 4+ caused by auto‐oxidation process. Importantly, the in situ Raman spectrum exhibits the vibration signal of Co–OH in the non‐Faradaic potential interval for oxygen evolution reaction, which is considered the initial step in reconstruction process. Density functional theory and ab initio molecular dynamics are used to elucidate this process at the atomic scale: First, OH − exhibits a lower adsorption energy barrier and proton desorption energy barrier at the configuration surface, which proposes the formation of a single oxygen (–O) group. Under a higher –O group coverage, the Co–P bond is destroyed along with the PO x groups. Subsequently, lower P vacancy formation energy confirm that the Ni‐CoP configuration can fast transform into a highly active phase. Based on the optimized reconstruction behavior and rate‐limiting barrier, the Ni‐CoP nanowire exhibit an excellent overpotential of 1.59 V at 10 mA cm −2 for overall water splitting, which demonstra...