The development of bifunctional electrocatalysts is an appealing yet challenging task for renewable energy conversion. Herein, taking core-shell structure as an example, we propose a “phase mediation” strategy to boost electronic synergism on hydrogen and oxygen evolution reaction (HER/OER). Through precisely tuning the cobalt cores from face-centered-cubic (fcc) to hexagonal (hcp) structure, the electrocatalytic overpotentials of [email protected] for both HER and OER are reduced by ∼100 mV, and lower than those of most other carbon-based electrocatalysts yet reported. Operando SR-FTIR measurements uncover key intermediates of *H and *O―O bonding to N and C sites of C―N moieties in [email protected] during the HER and OER processes, respectively, suggesting the adjacent C―N moieties as synergistic active sites. In addition, atomic-level characterizations combined with theoretical calculations reveal robust interfacial metal-ligand coordination and electron injection effect within [email protected] This promotes the delocalization of electronic structure of the NC shell, greatly accelerating overall water splitting.

双功能电催化剂的开发对于可再生能源的转化是一项有吸引力而又具有挑战性的任务。本文以核-壳结构为例，提出了一种“相调解”策略，以促进氢和氧放出反应（HER / OER）的电子协同作用。通过精确地将钴核从面心立方（fcc）调整为六方（hcp）结构，[电子邮件保护]对HER和OER的电催化超电势降低了约100 mV，并且低于大多数其他碳的电催化超电势。基电催化剂尚未报道。Operando SR-FTIR测量发现在HER和OER过程中，[H]和* O-O分别与[电子邮件保护]中C-N部分的N和C位键合的关键中间体，表明相邻的C-N部分具有协同作用活动站点。此外，