•  
  •  
 
Nano Research

Article Title

Hydrogen evolution activity enhancement by tuning the oxygen vacancies in self-supported mesoporous spinel oxide nanowire arrays

Authors

Dali Liu, Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin 300072, China Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China
Chao Zhang, Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin 300072, China
Yifu Yu, Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin 300072, China Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Yanmei Shi, Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin 300072, China
Yu Yu, Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin 300072, China
Zhiqiang Niu, Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China
Bin Zhang, Department of Chemistry, School of Science, and Tianjin Key Laboratory of Molecular Optoelectronic Science, Tianjin University, Tianjin 300072, China Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University, Tianjin 300071, China

Keywords

electrochemical activation, hydrogen evolution reaction, oxygen vacancy, spinel phase, thermal treatment

Abstract

ABSTRACT The development of facile strategies to tune the oxygen vacancy (OV) content in transition metal oxides (TMOs) is paramount to obtain low-cost and stable electrocatalysts, but still highly challenging. Taking NiCo2O4 as a model system, we have experimentally established a facile calcination and electrochemical activation (EA) methodology to dramatically increase the concentration of OVs and provide theoretical insight into how the concentration of OVs affects the performance of spinel TMOs towards the electrochemical hydrogen evolution reaction (HER). A self-supported cathode of OV-rich NiCo2O4 nanowire arrays was found to exhibit higher HER activity and better stability in alkaline media than its counterparts with fewer OVs. The electrocatalytic HER activity was in good agreement with the increasing concentration of OVs in the studied samples. A large current density of 360 mA·cm–2 was reached with an overpotential of only 317 mV. Additionally, such a facile strategy was able to efficiently generate OVs in other TMOs (e.g., CoFe2O4 and NiFe2O4) for enhanced HER performance. In addition, our theoretical results suggest that the increasing OV concentration reduces the adsorption energy of water molecules and their dissociation energy barrier on the surface of the catalyst, thus leading to performance improvement of spinel TMOs toward the electrochemical HER. This work may open a new avenue to increase the concentration of OVs in TMOs in a controlled manner for promising applications in a variety of fields.

Graphical Abstract

Publisher

Tsinghua University Press

Share

COinS