Molten salt method synthesis of multivalent cobalt and oxygen vacancy modified Nitrogen-doped MXene as highly efficient hydrogen and oxygen Evolution reaction electrocatalysts

Xunxin Chen; Meishan Li; Juan Hou; Ke Lu; Xuanyu Yue; Yafei Li; Long Chen; Zhiyong Liu; Xiaodong Yang

doi:10.1016/j.jcis.2022.02.010

Molten salt method synthesis of multivalent cobalt and oxygen vacancy modified Nitrogen-doped MXene as highly efficient hydrogen and oxygen Evolution reaction electrocatalysts

J Colloid Interface Sci. 2022 Jun:615:831-839. doi: 10.1016/j.jcis.2022.02.010. Epub 2022 Feb 7.

Authors

Xunxin Chen¹, Meishan Li², Juan Hou³, Ke Lu⁴, Xuanyu Yue⁴, Yafei Li⁴, Long Chen⁴, Zhiyong Liu⁴, Xiaodong Yang⁵

Affiliations

¹ College of Science/Key Laboratory of Ecophysics and Department of Physics, Shihezi University, Shihezi 832003, Xinjiang, China; School of Chemistry and Chemical Engineering/Key Laboratory for Green Process of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, Xinjiang, China.
² College of Science/Key Laboratory of Ecophysics and Department of Physics, Shihezi University, Shihezi 832003, Xinjiang, China.
³ College of Science/Key Laboratory of Ecophysics and Department of Physics, Shihezi University, Shihezi 832003, Xinjiang, China. Electronic address: [email protected].
⁴ School of Chemistry and Chemical Engineering/Key Laboratory for Green Process of Chemical Engineering of Xinjiang Bingtuan, Shihezi University, Shihezi 832003, Xinjiang, China.
⁵ College of Science/Key Laboratory of Ecophysics and Department of Physics, Shihezi University, Shihezi 832003, Xinjiang, China. Electronic address: [email protected].

PMID: 35180631
DOI: 10.1016/j.jcis.2022.02.010

Abstract

Nitrogen-doped Ti₃C₂T_y MXene with multivalent cobalt and oxygen vacancy (Vo) modification was obtained by using molten salt method and greatly improved electrocatalytic performance. The structural properties of MXene and the valence state of cobalt were adjusted by controlling the molten salt temperature. When the molten salt treatment temperature was 377 °C, the obtained 377-CoO_xN_1-x-Ti₃C₂T_y maintained the chemical structure of MXene well, and also has high Co²⁺ content and Vo content. Electrochemical test results showed that 377-CoO_xN_1-x-Ti₃C₂T_y had the lowest Hydrogen Evolution Reaction (HER) overpotential of 87.73 mV and good electrocatalytic stability. X-ray Photoelectron Spectroscopy (XPS) results and Density Functional Theory (DFT) calculations showed that the introduction of polyvalent cobalt and Vo in the nitrogen-doped Ti₃C₂T_y structure effectively reduced the energy barrier of the electrocatalytic reaction of MXene.

Keywords: Hydrogen Evolution Reaction; MXene; Molten salt method; Multivalent cobalt; Oxygen Evolution Reaction; Oxygen vacancy.