The AlB₂-type WB₂-191 with only graphene-like flat boron layers is deemed to be an ideal electrocatalyst for hydrogen evolution. However, such investigation is severely hindered by the lack of facile synthesis methods for this type of WB₂-191. Herein, we report the successful synthesis of AlB₂-type WB₂-191 by a one-step molten salt method via the reaction of WCl₆ and NaBH₄ in LiCl–KCl molten salt at 800 °C under atmospheric pressure. The as-synthesized WB₂-191 presents a nanosheet structure, as demonstrated by the scanning electron microscope and transmission electron microscopy results with a large BET surface area of 63 m²/g. Such WB₂-191 nanosheets exhibit remarkable hydrogen evolution reaction activity, delivering low overpotentials of 121 in 0.5 H₂SO₄ and 147 mV in 1.0 M KOH to drive 10 mA/cm², which is superior to any previously reported binary tungsten borides. Furthermore, an outstanding stability was shown over 70 h of potentiostatic operations in both acidic and alkaline electrolytes.

中文翻译：

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二硼化钨 （WB2-191） 在熔盐中的简单合成及其在酸性和碱性介质中的析氢性能


仅具有类似石墨烯的扁平硼层的 AlB₂ 型 WB 2-191 被认为是析氢的理想电催化剂。然而，由于缺乏针对此类 WB 2-191 的简单合成方法，这种研究受到严重阻碍。在此，我们报道了在 800 °C 大气压下，_{WCl 6} 和 NaBH₄ 在 LiCl-KCl 熔盐中反应，通过一步熔盐法成功合成 AlB₂ 型 WB 2-191。合成的 WB 2-191 呈现纳米片结构，扫描电子显微镜和透射电子显微镜结果证明其 BET 表面积大，为 63 m²/g。这种 WB 2-191 纳米片表现出显着的析氢反应活性，在 0.5 H₂SO₄ 中提供 121 的低过电位，在 1.0 M KOH 中提供 147 mV 的低过电位，以驱动 10 mA/cm²，这优于以前报道的任何二元硼化钨。此外，在酸性和碱性电解质中，在 70 小时的恒电操作中均显示出出色的稳定性。