Strong Bonding of Lattice N Activates Metal Ni to Achieve Efficient Water Splitting
Nian-Dan Zhao, Wei Luo, Sijun Li, Hua Wang, Yini Mao, Yimin Jiang, Wenbin Wang, Ming Li, Wei‐Fang Su, Rongxing He
Abstract
Abstract Developing efficient and robust free‐standing electrocatalysts for overall water splitting is a promising but challenging task. Herein, the N‐incorporated Ni nanosheets non‐fully encapsulated by N‐doped carbon (NC) layer are fabricated (N─Ni©NC). The introduction of N not only regulates the size of nanosheets in N─Ni©NC but also promotes the electrochemical activity of metal Ni. Experimental and theoretical results reveal that strong bonding of the lattice N activates the inert metal Ni by promoting charge transfer between Ni and N. In addition, the upward shift of the d‐band center induced by lattice N enhances the adsorption of intermediates, thereby making Ni as a new OER active site together with C. This strategy of generating Ni and C dual active sites by introducing lattice N greatly accelerates oxygen evolution reaction (OER) kinetics, resulting in excellent electrocatalytic performance of N─Ni©NC. At the current density of 10 mA cm −2 , the overpotentials of hydrogen evolution reaction (HER) and OER are 27 and 206 mV, respectively, and the cell voltage for overall water splitting only needs 1.47 V. This work offers a unique heteroatom activation approach for designing free‐standing electrodes with high activity.