2D Bismuth nanosheet arrays as efficient alkaline hydrogen evolution electrocatalysts.

Hydrogen evolution catalysts have been studied more in the aspect of iron series elements and less in bismuth metal. Bismuth-based materials are widely used in photocatalysis and CO₂ reduction and are rarely applied as electrocatalysts of hydrogen evolution. Meanwhile, the quantum confinement effect and electronic structure of materials will be significantly improved by decreasing the dimension of catalytic materials. Therefore, 2D bismuth nanosheets grown on nickel foam (Bi/NF) by a one-pot method are applied to hydrogen evolution. The catalysts with different reaction times were prepared to optimize the catalytic structure and improve the reactivity. The optimal Bi/NF was obtained with the reaction time of 24 h, which appears as 2D nanosheet arrays. According to the experimental results, the modified Bi/NF displays an overpotential −176 mV at −10 mA cm⁻² for hydrogen evolution reaction (HER) in 1 M KOH, which could be used as a working electrode continuously and stably electrolyzed for 10 h. This work looks forward to expanding the application of bismuth metal and broadening the scope of research on hydrogen evolution reactions. In addition, it provides new strategies for constructing efficient and low-cost HER catalysts. [ABSTRACT FROM AUTHOR]