One-step spontaneous growth of NiFe layered double hydroxide at room temperature for seawater oxygen evolution. (July 2021)

• Record Type: Journal Article
• Authors: Ning, M.; Wu, L.; Zhang, F.; Wang, D.; Song, S.; Tong, T.; Bao, J.; Chen, S.; Yu, L.; Ren, Z.
• Is Part Of: Materials today physics. Volume 19(2021)
• Publication Date: 2021-07
• Subjects: Seawater splitting -- Oxygen evolution reaction -- NiFe layered Double hydroxides -- Water electrolysis; Materials science -- Periodicals; Physics -- Periodicals; Electronic journals; 530.41
• DOI: 10.1016/j.mtphys.2021.100419
• Languages: English
• ISSNs: 2542-5293

Abstract

Abstract: Electrochemical seawater splitting is a promising technique because it addresses two major challenges, clean energy production and seawater desalination, at the same time. Therefore, seeking out a facile and cost-effective way to synthesize highly active and stable seawater-splitting catalysts is of great interest to both the research community and industry. Here we developed an Fe 2+ -driven, one-step, and spontaneous fabrication method for a seawater-oxygen-evolution-active NiFe layered double hydroxide (LDH) at room temperature. The NiFe LDH was found to exhibit very high activity and stability toward the oxygen evolution reaction (OER) in an alkaline natural seawater electrolyte, delivering current densities of 100 and 500 mA/cm 2 at low overpotentials of 247 and 296 mV, respectively, and with no significant degradation observed over long-term stability testing of 96 h under a large current density of 500 mA/cm 2 in 1 M KOH seawater electrolyte. After coupling with a good hydrogen evolution reaction (HER) catalyst, NiMoN, the two-electrode electrolyzer was found to achieve current densities of 10, 100, and 500 mA/cm 2 at voltages of 1.477, 1.533, and 1.665 V, respectively, in alkaline natural seawater with good durability over 100 h at 500 mA/cm 2 . The oxidation of Fe 2+ is the driving force for the growth of NiFe LDH, and this mechanism is universal to the fabrication of other Fe-based hydroxides as efficient OER catalysts. Graphical abstract: Image 1 Highlights: New method for the fabrication of NiFe LDH under room temperature without assists from electrochemical equipment. Highly active seawater oxygen evolution reaction catalyst with extremely low investment. Durable seawater electrolyzer withstands high current density of 500 mA/cm 2 over 100 h.