Moving beyond bimetallic-alloy to single-atom dimer atomic-interface for all-pH hydrogen evolution

Ashwani Kumar; Viet Q Bui; Jinsun Lee; Lingling Wang; Amol R Jadhav; Xinghui Liu; Xiaodong Shao; Yang Liu; Jianmin Yu; Yosep Hwang; Huong T D Bui; Sara Ajmal; Min Gyu Kim; Seong-Gon Kim; Gyeong-Su Park; Yoshiyuki Kawazoe; Hyoyoung Lee

doi:10.1038/s41467-021-27145-3

Moving beyond bimetallic-alloy to single-atom dimer atomic-interface for all-pH hydrogen evolution

Nat Commun. 2021 Nov 19;12(1):6766. doi: 10.1038/s41467-021-27145-3.

Authors

Ashwani Kumar^#^{1

2}, Viet Q Bui^#^{1

2}, Jinsun Lee^{1

2}, Lingling Wang^{1

2}, Amol R Jadhav¹, Xinghui Liu^{1

2}, Xiaodong Shao^{1

2}, Yang Liu^{1

2}, Jianmin Yu^{1

2}, Yosep Hwang^{1

2}, Huong T D Bui^{1

2}, Sara Ajmal^{1

2}, Min Gyu Kim³, Seong-Gon Kim⁴, Gyeong-Su Park⁵, Yoshiyuki Kawazoe⁶, Hyoyoung Lee^{7

8

9

10}

Affiliations

¹ Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Korea.
² Department of Chemistry, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea.
³ Beamline Research Division, Pohang Accelerator Laboratory (PAL), Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.
⁴ Department of Physics and Astronomy and Center for Computational Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.
⁵ Department of Materials Science and Engineering, and Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea.
⁶ New Industry Creation Hatchery Center, Tohoku University, Sendai, 980-8579, Japan.
⁷ Center for Integrated Nanostructure Physics (CINAP), Institute for Basic Science (IBS), Sungkyunkwan University, Suwon, 16419, Korea. hyoyoung@skku.edu.
⁸ Department of Chemistry, Sungkyunkwan University (SKKU), Suwon, 16419, Republic of Korea. hyoyoung@skku.edu.
⁹ Department of Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea. hyoyoung@skku.edu.
¹⁰ Creative Research Institute, Sungkyunkwan University, Suwon, 16419, Republic of Korea. hyoyoung@skku.edu.

^# Contributed equally.

Abstract

Single-atom-catalysts (SACs) afford a fascinating activity with respect to other nanomaterials for hydrogen evolution reaction (HER), yet the simplicity of single-atom center limits its further modification and utilization. Obtaining bimetallic single-atom-dimer (SAD) structures can reform the electronic structure of SACs with added atomic-level synergistic effect, further improving HER kinetics beyond SACs. However, the synthesis and identification of such SAD structure remains conceptually challenging. Herein, systematic first-principle screening reveals that the synergistic interaction at the NiCo-SAD atomic interface can upshift the d-band center, thereby, facilitate rapid water-dissociation and optimal proton adsorption, accelerating alkaline/acidic HER kinetics. Inspired by theoretical predictions, we develop a facile strategy to obtain NiCo-SAD on N-doped carbon (NiCo-SAD-NC) via in-situ trapping of metal ions followed by pyrolysis with precisely controlled N-moieties. X-ray absorption spectroscopy indicates the emergence of Ni-Co coordination at the atomic-level. The obtained NiCo-SAD-NC exhibits exceptional pH-universal HER-activity, demanding only 54.7 and 61 mV overpotentials at -10 mA cm^-2 in acidic and alkaline media, respectively. This work provides a facile synthetic strategy for SAD catalysts and sheds light on the fundamentals of structure-activity relationships for future applications.