Ru-regulated electronic structure CoNi-MOF nanosheets advance water electrolysis kinetics in alkaline and seawater media

Wenqiang Li; Bowen Guo; Ka Zhang; Xueyi Chen; Heng Zhang; Wanyu Chen; Haipeng Chen; Huabo Li; Xun Feng

doi:10.1016/j.jcis.2024.04.144

Ru-regulated electronic structure CoNi-MOF nanosheets advance water electrolysis kinetics in alkaline and seawater media

J Colloid Interface Sci. 2024 Apr 21:668:181-189. doi: 10.1016/j.jcis.2024.04.144. Online ahead of print.

Authors

Wenqiang Li¹, Bowen Guo², Ka Zhang³, Xueyi Chen³, Heng Zhang¹, Wanyu Chen¹, Haipeng Chen¹, Huabo Li⁴, Xun Feng⁵

Affiliations

¹ College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, PR China.
² College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, PR China; College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473601, PR China.
³ College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, PR China; College of Chemistry, Zhengzhou University, Zhengzhou 450001, PR China.
⁴ Guangdong Alcohol and Hydrogen New Energy Research Institute Co., Ltd., Guangzhou 511316, PR China.
⁵ College of Chemistry and Chemical Engineering, Luoyang Normal University, Luoyang 471934, PR China. Electronic address: fengx@lynu.edu.cn.

PMID: 38677207
DOI: 10.1016/j.jcis.2024.04.144

Abstract

Herein, an ion-exchange strategy is utilized to greatly improve the kinetics of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) by Ru-modified CoNi- 1,3,5-Benzenetricarboxylic acid (BTC)-metal organic framework nanosheets (Ru@CoNi-MOF). Due to the higher Ni active sites and lower electron transfer impedance, Ru@CoNi-MOF catalyst requires the overpotential as low as 47 and 279 mV, at a current density of 10 mA/cm² toward HER and OER, respectively. Significantly, the mass activity of Ru@CoNi-MOF for HER and OER are 25.9 and 10.6 mA mg^-1, nearly 15.2 and 8.8 times higher than that of Ni-MOF. In addition, the electrolyzer of Ru@CoNi-MOF demonstrates exceptional electrolytic performance in both KOH and seawater environment, surpasses the commercial Pt/C||IrO₂ couple. Theoretical calculations prove that introducing Ru atoms in - CoNi-MOF modulates the electronic structure of Ni, optimizes adsorption energy for H* and reduces energy barrier of metal organic frameworks (MOFs). This modification significantly improves the kinetic rate of the Ru@CoNi-MOF during water splitting. Certainly, this study highlights the utilization of MOF nanosheets as advanced HER/OER electrocatalysts with immense potential, and will paves a way to develop more efficient MOFs for catalytic applications.

Keywords: Alkaline seawater; Hydrogen evolution reaction; Ion-exchange strategy; Oxygen evolution reaction; Ru@CoNi-MOF nanosheets.