Electronic distribution tuning of vanadium-cobalt bimetallic MOFs for highly efficient hydrazine-assisted energy-saving hydrogen production. (20th January 2023)

• Record Type: Journal Article
• Authors: Fang, Wenhui; Dang, Jiaqi; Hu, Ye; Wu, Ying; Xin, Shixian; Chen, Bozhen; Zhao, Hong; Li, Zengxi
• Is Part Of: Electrochimica acta. Volume 439(2023)
• Publication Date: 2023-01-20
• Subjects: Electronic redistribution tuning -- V-doping -- Interface -- Hydrazine oxidation reaction -- Energy-saving electrolysis; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.141682
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Substituting oxygen evolution reaction (OER) by hydrazine oxidation reaction (HzOR) is a very efficient energy-saving strategy for water electrolysis. Therefore, exploring low-cost and efficient catalysts for HzOR and hydrogen evolution reaction (HER) is very significant to address the great challenge for hydrogen production. Herein, a series of vanadium-cobalt bimetal-organic frameworks [Vx -Co-MOFs: x represents the mass fraction of V element: V/(V+Co)] are synthesized through a one-pot hydrothermal method. The V41.7wt% -Co-MOF exhibits excellent multifunctional catalytic activity. The overall hydrazine splitting (OHzS) delivers 10 mA cm −2 at an ultralow cell voltage of 0.21 V. The superior performance can be ascribed to that the presence of cobalt-vanadium bimetals, which leads to the lattice disorder, an increase in specific surface area and mesoporous structure in V41.7wt% -Co-MOF, thus ensuring the exposure of more active sites. Particularly, the in-situ Raman test indicates that V41.7wt% -Co-MOF is partially converted into Co(OH)2 in the process of electrolysis to form a heterostructure. DFT calculations further show the charge transfer between Co and V, along with the good synergy between V-Co-MOF and Co(OH)2 improves the HER and HzOR performance of V41.7wt% -Co-MOF. This study provides a promising Co-V based catalyst for energy saving hydrogen production. Graphical abstract: V41.7wt% -Co-MOF metal compound as bifunctional catalyst for effective hydrogen production with hydrazine-assisted. Image, graphical abstract