Effects of carbon defects on interfacial anchoring of NiFe-LDH for seawater electro-oxidation

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 11; no. 19; pp. 1277 - 1286
• Main Authors: Xu, Heng, Xie, Shi-Jun, Lv, Chao, Li, Jun-Tao, Zhou, Yao, Sun, Shi-Gang
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 16.05.2023
• Subjects: Anions; Contact resistance; Covalent bonds; Defects; Electrocatalysts; Electrochemistry; Etching; Interface stability; Intermetallic compounds; Iron compounds; Nickel compounds; Oxidation; Oxygen evolution reactions; Seawater
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d2ta09562a

The solid-solid interfacial intimacy between the current collector and electrocatalyst is of profound importance in any electrochemical process. Herein, we report that the carbonaceous current collector with high defect density tends to form interfacial C-O-M covalent bonds with the metal sites of NiFe-LDH nanosheets. Such interfacial oxygen bridges on one hand decrease the ohmic contact impedance between the electrocatalyst and current collector, promoting the surface reconstruction of NiFe-LDH and boosting the electrocatalytic activity for the oxygen evolution reaction, and the electrocatalyst-peeling-off phenomenon caused by the coordinative etching of halide anions during seawater electrooxidation, can also be effectively suppressed, on the other hand. The optimal electrode can work steadily for more than 600 h under 500 mA cm −2 in alkaline natural seawater, showing significantly improved solid-solid interfacial stability. Carbon defects are found to enhance solid-solid interfacial stability between NiFe-LDH and the carbon current collector and effectively suppress the nasty electrocatalyst-peeling off phenomenon during seawater electro-oxidation.