1. Nanorod-like NiFe metal-organic frameworks for oxygen evolution in alkaline seawater media.
- Author
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Xiao, Liyuan, Han, Jingyi, Wang, Zhenlu, and Guan, Jingqi
- Subjects
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METAL-organic frameworks , *OXYGEN evolution reactions , *HYDROGEN evolution reactions , *SEAWATER , *ACTIVATION energy , *IRON-nickel alloys , *CHARGE transfer - Abstract
Searching for highly active and durable oxygen evolution reaction (OER) electrocatalysts is the key to break through the bottleneck of overall water splitting. Here, we prepare Ni x Fe-BDC (H 2 BDC = terephthalic acid) nanorods with different Ni/Fe ratios by a facile solvothermal method for the OER. The optimal Ni 3 Fe-BDC exhibits a low overpotential (η 10) of 265 mV and a Tafel slope of 90 mV·dec−1 in 1 M KOH. Moreover, it shows a low η 10 of 280 mV and excellent stability in the mixture of 1 M NaCl and 1 M KOH, which has strong corrosion resistance to Cl− anions. The role of Fe3+ not only increases the charge transfer rate of Ni 3 Fe-BDC, but also affects the specific surface area of the catalyst with high electrochemical activity. Kinetic studies show that both Fe and Ni sites act as active centers, which catalyze synergistically to reduce the reaction kinetic energy barrier. Characterization results of the used Ni 3 Fe-BDC reveal that the in situ formed rod-like Ni 3 FeOOH is the active site for the OER. Ni 3 Fe-BDC shows low η 10 of 265 mV and 280 mV for the OER in 1 M KOH and in 1 M NaCl + 1 M KOH, respectively. In situ transformation of nanorod-like Ni 3 Fe-BDC MOF to Ni 3 FeOOH can efficiently remain the advantages of MOF, e.g. porous structure, high specific surface area and uniformly dispersed metal sites. [Display omitted] • Ni 3 Fe-BDC shows low η 10 of 265 mV for the OER in 1 M KOH. • Ni 3 Fe-BDC shows η 10 of only 280 mV for the OER in 1 M NaCl +1 M KOH. • Ni 3 Fe-BDC exhibits a low OER energy barrier of 13.7 kJ/mol. • The in-situ formed rod-like Ni 3 FeOOH serves as efficient active site for the OER. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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