Molten salt derived Mo₂AlB₂ with excellent HER catalytic performance

Abstract

Mo₂AlB₂ is a lamellar transition metal boride that is prepared by selectively etching the MoAlB MAB phase precursor. Most methods for synthesizing Mo₂AlB₂ require the use of strong acids or bases and a long reaction time. In this study, we present a Lewis acid molten salt method for synthesizing the lamellar structured Mo₂AlB₂ by selectively etching a layer of aluminium atoms from the MoAlB precursor. The synthesized Mo₂AlB₂ shows excellent catalytic activity for hydrogen evolution reaction under alkaline conditions, with long-term stability, and a low overpotential of 145 mV and Tafel slope of 76 mV dec⁻¹ at 10 mA cm⁻².

GRAPHICAL ABSTRACT

IMPACT STATEMENT

Mo₂AlB₂ was synthesized through a novel molten salt method of etching MoAlB, resulting in exceptional HER catalytic performance in alkaline conditions.

KEYWORDS:

• MoAlB
• molten salt synthesis
• Mo₂AlB₂
• HER

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the National Natural Science Foundation of China [grant number 52072252], and the Science Fund of Sichuan Province for Distinguished Young Scholars [grant number 2023NSFSC1942].