Self-driven Ru-modified NiFe MOF nanosheet as multifunctional electrocatalyst for boosting water and urea electrolysis

Yuan Wang; Cheng Wang; Hongyuan Shang; Mengyu Yuan; Zhengying Wu; Jie Li; Yukou Du

doi:10.1016/j.jcis.2021.07.124

Self-driven Ru-modified NiFe MOF nanosheet as multifunctional electrocatalyst for boosting water and urea electrolysis

J Colloid Interface Sci. 2022 Jan:605:779-789. doi: 10.1016/j.jcis.2021.07.124. Epub 2021 Jul 30.

Authors

Yuan Wang¹, Cheng Wang¹, Hongyuan Shang¹, Mengyu Yuan¹, Zhengying Wu², Jie Li¹, Yukou Du³

Affiliations

¹ College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, PR China.
² Jiangsu Key Laboratory for Environment Functional Materials, School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China. Electronic address: zywu@mail.usts.edu.cn.
³ College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, PR China. Electronic address: duyk@suda.edu.cn.

PMID: 34371423
DOI: 10.1016/j.jcis.2021.07.124

Abstract

Urea electro-oxidation reaction (UOR) has been a promising strategy to replace oxygen evolution reaction (OER) by urea-mediated water splitting for hydrogen production. Naturally, rational design of high-efficiency and multifunctional electrocatalyst towards UOR and hydrogen evolution reaction (HER) is of vital significance, but still a grand challenge. Herein, an innovative 3D Ru-modified NiFe metal-organic framework (MOF) nanoflake array on Ni foam (Ru-NiFe-x/NF) was elaborately designed via spontaneous galvanic replacement reaction (GRR). Notably, the adsorption capability of intermediate species (H*) of catalyst is significantly optimized by Ru modification. Meanwhile, rich high-valence Ni active species can be acquired by self-driven electronic reconstruction in the interface, then dramatically accelerating the electrolysis of water and urea. Remarkably, the optimized Ru-NiFe-③/NF (1.6 at% of Ru) only requires the overpotential of 90 and 310 mV to attain 100 mA cm^-2 toward HER and OER in alkaline electrolyte, respectively. Impressively, an ultralow voltage of 1.47 V is required for Ru-NiFe-③/NF to deliver a current density of 100 mA cm^-2 in urea-assisted electrolysis cell with superior stability, which is 190 mV lower than that of Pt/C-NF||RuO₂/NF couple. This work is desired to explore a facile way to exploit environmentally-friendly energy by coupling hydrogen evolution with urea-rich sewage disposal.

Keywords: Galvanic replacement reaction; Metal-organic frameworks (MOFs) derivative; Multifunctional electrocatalyst; Water and urea electrolysis.