Tungstate Intercalated NiFe Layered Double Hydroxide Enables Long‐Term Alkaline Seawater Oxidation
Hefeng Wang, Zixiao Li, Shaohuan Hong, Chaoxin Yang, Jie Liang, Kai Dong, Hui Zhang, Xiaoyan Wang, Min Zhang, Shengjun Sun, Yongchao Yao, Yongsong Luo, Qian Liu, Luming Li, Wei Chu, Miao Du, Feng Gong, Xuping Sun, Bo Tang
Abstract
Abstract Renewable electricity‐driven seawater splitting presents a green, effective, and promising strategy for building hydrogen (H 2 )‐based energy systems (e.g., storing wind power as H 2 ), especially in many coastal cities. The abundance of Cl − in seawater, however, will cause severe corrosion of anode catalyst during the seawater electrolysis, and thus affect the long‐term stability of the catalyst. Herein, seawater oxidation performances of NiFe layered double hydroxides (LDH), a classic oxygen (O 2 ) evolution material, can be boosted by employing tungstate (WO 4 2– ) as the intercalated guest. Notably, insertion of WO 4 2− to LDH layers upgrades the reaction kinetics and selectivity, attaining higher current densities with ≈100% O 2 generation efficiency in alkaline seawater. Moreover, after a 350 h test at 1000 mA cm −2 , only trace active chlorine can be detected in the electrolyte. Additionally, O 2 evolution follows lattice oxygen mechanism on NiFe LDH with intercalated WO 4 2− .