Li Nannan, Han Xiaotong, Park Ho Seok, Lee Jin Yong
Department of Chemistry, Institute of Basic Science, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, China.
Phys Chem Chem Phys. 2025 Jun 18;27(24):13011-13020. doi: 10.1039/d5cp01202c.
Transition metal-based layered double hydroxides (TM-LDHs) are among the most promising catalytic materials for the electrochemical reactions involved in energy conversion and storage technology. We systematically investigate NiFe-LDH-based electrocatalysts toward application in water electrolysis. We start with the highly accurate advanced density functional theory description of NiFe-LDH's fundamental properties, and demonstrate that coupling a spin-polarized p-band or d-band center model with the Gibbs free energy calculations explains NiFe-LDH's oxygen evolution reaction (OER) mechanism. By involving the related transient states, a reversible oxygen vacancy assisted reaction mechanism has been directly observed and motivated by the high spin transition metal impurity which is further confirmed by the time-consuming hybrid functional method. To further facilitate the electrocatalytic activity of NiFe-LDH, we study NiFe-LDH/MXene heterostructures where the essential semiconductor-to-metallic transition takes place by the additional Ti-3d orbitals and the interfacial non-covalent interaction between the two catalysts. On the basis of calculated results, we propose a link between microscopic properties and macroscopic electrocatalytic kinetics of heterogenous electrocatalysts. Accurately describing the electronic and magnetic structures of electrocatalysts leads us to a step-by-step process for tailoring desired electrocatalytic properties, especially for the high spin state contained TM-LDHs. A descriptor based on combination of the calculated d-band center of transition metal and p-band center of oxygen is the key to predicting electrochemical activity and stability of oxide electrocatalysts. From our results, we establish a design strategy for NiFe-LDH-based bifunctional electrocatalyst fabrication.
过渡金属基层状双氢氧化物（TM-LDHs）是能量转换和存储技术中涉及的电化学反应最有前景的催化材料之一。我们系统地研究了用于水电解的基于NiFe-LDH的电催化剂。我们从对NiFe-LDH基本性质的高精度先进密度泛函理论描述开始，并证明将自旋极化的p带或d带中心模型与吉布斯自由能计算相结合可以解释NiFe-LDH的析氧反应（OER）机理。通过涉及相关的瞬态，直接观察到了一种可逆的氧空位辅助反应机理，该机理由高自旋过渡金属杂质引发，耗时的杂化泛函方法进一步证实了这一点。为了进一步促进NiFe-LDH的电催化活性，我们研究了NiFe-LDH/MXene异质结构，其中通过额外的Ti-3d轨道以及两种催化剂之间的界面非共价相互作用发生了从半导体到金属的关键转变。基于计算结果，我们提出了异质电催化剂微观性质与宏观电催化动力学之间的联系。准确描述电催化剂的电子和磁性结构使我们能够逐步定制所需的电催化性能，特别是对于包含高自旋态的TM-LDHs。基于过渡金属计算的d带中心和氧的p带中心组合的描述符是预测氧化物电催化剂电化学活性和稳定性的关键。根据我们的结果，我们建立了一种基于NiFe-LDH的双功能电催化剂制备的设计策略。
