Journal Article

Multiscale Engineering of Nonprecious Metal Electrocatalyst for Realizing Ultrastable Seawater Splitting in Weakly Alkaline Solution

Yu, Tingting, Lei, Linfeng, Li, Jiankun, Zhuang, Linzhou, Wang, Yixing, Lian, Cheng, Shao, Zongping, He, Juan, Zhu, Minghui, Xu, Zhi, Li, Zhiheng, Wang, Keyu

2022

Overview

Seawater electrolysis is an attractive technique for mass production of high‐purity hydrogen considering the abundance of seawater. Nevertheless, due to the complexity of seawater environment, efficient anode catalyst, that should be, cost effective, highly active for oxygen evolution reaction (OER) but negligible for Cl2/ClO– formation, and robust toward chlorine corrosion, is urgently demanded for large‐scale application. Although catalysis typically appears at surface, while the bulk properties and morphology structure also have a significant impact on the performance, thus requiring a systematic optimization. Herein, a multiscale engineering approach toward the development of cost‐effective and robust OER electrocatalyst for operation in seawater is reported. Specifically, the engineering of hollow‐sphere structure can facilitate the removal of gas product, while atom‐level synergy between Co and Fe can promote Co sites transforming to active phase, and in situ transformation of sulfate ions layer protects catalysts from corrosion. As a result, the as‐developed hollow‐sphere structured CoFeSx electrocatalyst can stably operate at a high current density of 100 mA cm–2 in the alkaline simulated seawater (pH = 13) for 700 h and in a neutral seawater for 20 h without attenuation. It provides a new strategy for the development of electrocatalysts with a broader application potential. The hollow sphere CoFeSx (H‐CoFeSx) is developed into a highly efficient and robust seawater oxidation electrocatalyst by multiscale engineering via structural construction, in situ protection layer formation, and Fe‐doping for performance enhancement and anticorrosion. H‐CoFeSx could achieve a current density of 150 mA cm–2 at the overpotential of 420 mV and maintained at 100 mA cm–2 for 700 h with no performance degradation.

• Publisher: John Wiley & Sons, Inc,John Wiley and Sons Inc,Wiley
• Subject: Adsorption / Carbon / Corrosion / Electrodes / Electrolytes / Green hydrogen / hollow sphere / in situ Raman / long‐term stability / Pore size / Seawater / seawater splitting / Transmission electron microscopy / XAS