Dynamic evolution and reversibility of single-atom Ni(II) active site in 1T-MoS2 electrocatalysts for hydrogen evolution

Brian Pattengale; Yichao Huang; Xingxu Yan; Sizhuo Yang; Sabrina Younan; Wenhui Hu; Zhida Li; Sungsik Lee; Xiaoqing Pan; Jing Gu; Jier Huang

doi:10.1038/s41467-020-17904-z

Dynamic evolution and reversibility of single-atom Ni(II) active site in 1T-MoS₂ electrocatalysts for hydrogen evolution

Nat Commun. 2020 Aug 17;11(1):4114. doi: 10.1038/s41467-020-17904-z.

Authors

Brian Pattengale¹, Yichao Huang^{2

3}, Xingxu Yan⁴, Sizhuo Yang¹, Sabrina Younan², Wenhui Hu¹, Zhida Li², Sungsik Lee⁵, Xiaoqing Pan^{4

6}, Jing Gu⁷, Jier Huang⁸

Affiliations

¹ Department of Chemistry, Marquette University, Milwaukee, WI, 53201, USA.
² Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92181, USA.
³ Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, 100084, Beijing, PR China.
⁴ Department of Materials Science and Engineering, University of California, Irvine, CA, 92697, USA.
⁵ X-ray Science Division, Argonne National Laboratory, Argonne, IL, 60349, USA.
⁶ Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA.
⁷ Department of Chemistry and Biochemistry, San Diego State University, San Diego, CA, 92181, USA. jgu@sdsu.edu.
⁸ Department of Chemistry, Marquette University, Milwaukee, WI, 53201, USA. jier.huang@marquette.edu.

Abstract

1T-MoS₂ and single-atom modified analogues represent a highly promising class of low-cost catalysts for hydrogen evolution reaction (HER). However, the role of single atoms, either as active species or promoters, remains vague despite its essentiality toward more efficient HER. In this work, we report the unambiguous identification of Ni single atom as key active sites in the basal plane of 1T-MoS₂ (Ni@1T-MoS₂) that result in efficient HER performance. The intermediate structure of this Ni active site under catalytic conditions was captured by in situ X-ray absorption spectroscopy, where a reversible metallic Ni species (Ni⁰) is observed in alkaline conditions whereas Ni remains in its local structure under acidic conditions. These insights provide crucial mechanistic understanding of Ni@1T-MoS₂ HER electrocatalysts and suggest that the understanding gained from such in situ studies is necessary toward the development of highly efficient single-atom decorated 1T-MoS₂ electrocatalysts.

Abstract

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