Ternary Mo2 NiB2 as a Superior Bifunctional Electrocatalyst for Overall Water Splitting

Ali Saad; Yang Gao; Kwadwo Asare Owusu; Wei Liu; Yanyan Wu; Aymeric Ramiere; Haichuan Guo; Panagiotis Tsiakaras; Xingke Cai

doi:10.1002/smll.202104303

Ternary Mo₂ NiB₂ as a Superior Bifunctional Electrocatalyst for Overall Water Splitting

Small. 2022 Feb;18(6):e2104303. doi: 10.1002/smll.202104303. Epub 2021 Dec 2.

Authors

Ali Saad^{1

2}, Yang Gao³, Kwadwo Asare Owusu¹, Wei Liu¹, Yanyan Wu⁴, Aymeric Ramiere², Haichuan Guo⁵, Panagiotis Tsiakaras^{6

7

8}, Xingke Cai¹

Affiliations

¹ Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, P. R. China.
² College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
³ College of Materials Science and Engineering, Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, Hunan University, Changsha, 410082, PR China.
⁴ School of Science, Harbin Institute of Technology, Shenzhen, 518055, China.
⁵ Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, 315201, China.
⁶ Laboratory of Alternative Energy Conversion Systems, Department of Mechanical Engineering, School of Engineering, University of Thessaly, 1 Sekeri Str., Pedion Areos, 38834, Greece.
⁷ Laboratory of Materials and Devices for Clean Energy, Department of Technology of Electrochemical Processes, Ural Federal University, 19 Mira Str., Yekaterinburg, 620002, Russian Federation.
⁸ Laboratory of Electrochemical Devices Based on Solid Oxide Proton Electrolytes, Institute of High Temperature Electrochemistry (RAS), Yekaterinburg, 620990, Russian Federation.

PMID: 35142066
DOI: 10.1002/smll.202104303

Abstract

Transition metal borides are considered as promising electrocatalysts for water splitting due to their metallic conductivity and good durability. However, the currently reported monometallic and noncrystalline multimetallic borides only show generic and monofunctional catalytic activity. In this work, the authors design and successfully synthesize highly crystalline ternary borides, Mo₂ NiB₂ , via a facile solid-state reaction from pure elemental powders. The as-synthesized Mo₂ NiB₂ exhibits very low overpotentials for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), that is, 280 and 160 mV to reach a current density of 10 mA cm^-2 , in alkaline media. These values are much lower from the ones observed over monometallic borides, that is, Ni₂ B and MoB, and the lowest among all nonprecious metal borides. By loading Mo₂ NiB₂ onto Ni foams as both cathode and anode electrode for overall water splitting applications, a low cell voltage of 1.57 V is required to achieve a current density of 10 mA cm^-2 , comparable with the value required from the Pt/C||IrO₂ /C couple (1.56 V). The proposed synthesis strategy can be used for the preparation of cost-effective, multi-metallic crystalline borides, as multifunctional electrocatalysts.

Keywords: bifunctional electrocatalysts; crystalline Mo 2NiB 2; hydrogen evolution reaction (HER); oxygen evolution reaction (OER); ternary borides; water splitting.

Abstract

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