Modification of spinel MnCo2O4 nanowire with NiFe-layered double hydroxide nanoflakes for stable seawater oxidation

Nutthaphak Kitiphatpiboon; Meng Chen; Changrui Feng; Yifan Zhou; Changlin Liu; Zhongbao Feng; Qiang Zhao; Abuliti Abudula; Guoqing Guan

doi:10.1016/j.jcis.2022.11.044

Modification of spinel MnCo₂O₄ nanowire with NiFe-layered double hydroxide nanoflakes for stable seawater oxidation

J Colloid Interface Sci. 2023 Feb 15;632(Pt A):54-64. doi: 10.1016/j.jcis.2022.11.044. Epub 2022 Nov 13.

Authors

Nutthaphak Kitiphatpiboon¹, Meng Chen¹, Changrui Feng¹, Yifan Zhou², Changlin Liu¹, Zhongbao Feng³, Qiang Zhao⁴, Abuliti Abudula¹, Guoqing Guan⁵

Affiliations

¹ Graduate School of Science and Technology, Hirosaki University, 1-Bunkyocho, Hirosaki 036-8560, Japan.
² Energy Conversion Engineering Laboratory, Institute of Regional Innovation (IRI), Hirosaki University, 3-Bunkyocho, Hirosaki 036-8561, Japan; Graduate School of Sustainable Community Studies, Hirosaki University, 1-Bunkyocho, Hirosaki 036-8560, Japan.
³ Energy Conversion Engineering Laboratory, Institute of Regional Innovation (IRI), Hirosaki University, 3-Bunkyocho, Hirosaki 036-8561, Japan; School of Metallurgy, Liaoning Key Laboratory for Metallurgical Sensor and Technology, Northeastern University, Shenyang 110819, China.
⁴ School of Chemistry and Environmental Engineering, Shanxi Datong University, Datong 037009, China.
⁵ Graduate School of Science and Technology, Hirosaki University, 1-Bunkyocho, Hirosaki 036-8560, Japan; Energy Conversion Engineering Laboratory, Institute of Regional Innovation (IRI), Hirosaki University, 3-Bunkyocho, Hirosaki 036-8561, Japan. Electronic address: guan@hirosaki-u.ac.jp.

PMID: 36410294
DOI: 10.1016/j.jcis.2022.11.044

Abstract

Currently, direct electrolysis of seawater-based electrolytes rather than fresh water based ones for hydrogen production is gaining more and more attentions for creating a sustainable society. However, using seawater remains more challenges owing to the existence of competitive reactions between chlorine evolution reaction (ClER) or hypochlorite generation reaction and oxygen evolution reaction (OER) and electrode erosion. In this study, a MnCo₂O₄ nanowire coated with NiFe-Layered Double Hydroxide (NiFe-LDH) layer (MnCo₂O₄@NiFe-LDH) composite electrocatalyst prepared by a simple two-step hydrothermal method was applied for the seawater electrolysis, which exhibited low overpotentials of 219 and 245 mV at a relatively high current density of 100 mA cm^-2 in alkaline simulated and natural seawaters, respectively, as the anode electrocatalyst. It is found that the NiFe-LDH layer on the MnCo₂O₄ nanowire can serve as Cl^- protective layer to hinder the ClER and anode erosion and simultaneously improve the active surface area and intrinsic properties of MnCo₂O₄ nanowires, allowing for faster kinetics. While, the high valence states of Mn³⁺, Co³⁺, Ni³⁺and Fe³⁺ played a vital role for OER. In addition, when it was used as the bifunctional electrocatalyst for the overall real seawater splitting, the cell composed of MnCo₂O₄@NiFe-LDH (-) || MnCo₂O₄@NiFe-LDH (+) pair only required a low voltage of 1.56 V@10 mA cm^-2 and simultaneously maintained excellent stability at a high current density of 100 mA cm^-2. Such an electrocatalyst could be a promising candidate for long-term seawater splitting.

Keywords: Chloride blocking; Chlorine evolution reaction; Composite electrocatalyst; Core-shell structure; Oxygen evolution reaction; Seawater electrolysis.