Arming Amorphous NiMoO<sub>4</sub> on Nickel Phosphide Enables Highly Stable Alkaline Seawater Oxidation
Xiankun Guo, Xun He, Xuwei Liu, Shengjun Sun, Hang Sun, Kai Dong, Tengyue Li, Yongchao Yao, Ting Xie, Dongdong Zheng, Yongsong Luo, Jie Chen, Qian Liu, Luming Li, Wei Chu, Zhenju Jiang, Xuping Sun, Bo Tang
Abstract
Abstract Seawater electrolysis holds tremendous promise for the generation of green hydrogen (H 2 ). However, the system of seawater‐to‐H 2 faces significant hurdles, primarily due to the corrosive effects of chlorine compounds, which can cause severe anodic deterioration. Here, a nickel phosphide nanosheet array with amorphous NiMoO 4 layer on Ni foam (Ni 2 P@NiMoO 4 /NF) is reported as a highly efficient and stable electrocatalyst for oxygen evolution reaction (OER) in alkaline seawater. Such Ni 2 P@NiMoO 4 /NF requires overpotentials of just 343 and 370 mV to achieve industrial‐level current densities of 500 and 1000 mA cm −2 , respectively, surpassing that of Ni 2 P/NF (470 and 555 mV). Furthermore, it maintains consistent electrolysis for over 500 h, a significant improvement compared to that of Ni 2 P/NF (120 h) and Ni(OH) 2 /NF (65 h). Electrochemical in situ Raman spectroscopy, stability testing, and chloride extraction analysis reveal that is situ formed MoO 4 2− /PO 4 3− from Ni 2 P@NiMoO 4 during the OER test to the electrode surface, thus effectively repelling Cl − and hindering the formation of harmful ClO − .