具有高活性 MoB 中在析氢反应中具有相反活性的类石墨烯和类黑磷硼层。
Graphene- and Phosphorene-like Boron Layers with Contrasting Activities in Highly Active MoB for Hydrogen Evolution.
机构信息
Department of Chemistry, University of California, Riverside , Riverside, California 92521, United States.
Department of Chemical and Environmental Engineering, University of California, Riverside , Riverside, California 92521, United States.
出版信息
J Am Chem Soc. 2017 Sep 20;139(37):12915-12918. doi: 10.1021/jacs.7b07247. Epub 2017 Sep 8.
Two different boron layers, flat (graphene-like) and puckered (phosphorene-like), found in the crystal structure of MoB show drastically different activities for hydrogen evolution, according to Gibbs free energy calculations of H-adsorption on MoB. The graphene-like B layer is highly active, whereas the phosphorene-like B layer performs very poorly for hydrogen evolution. A new Sn-flux synthesis permits the rapid single-phase synthesis of MoB, and electrochemical analyses show that it is one of the best hydrogen evolution reaction active bulk materials with good long-term cycle stability under acidic conditions. MoB compensates its smaller density of active sites if compared with highly active bulk MoB (which contains only the more active graphene-like boron layers) by a 5-times increase of its surface area.
在 MoB 的晶体结构中发现了两种不同的硼层，分别是平坦的（类石墨烯）和褶皱的（类黑磷）。根据 H 在 MoB 上吸附的吉布斯自由能计算，这两种硼层对析氢反应表现出截然不同的活性。类石墨烯 B 层具有很高的活性，而类黑磷 B 层的析氢活性则非常差。一种新的 Sn 流体制备方法可以快速单相合成 MoB，电化学分析表明，在酸性条件下，它是最好的析氢反应活性体材料之一，具有良好的长期循环稳定性。与高活性块状 MoB（仅含有更活跃的类石墨烯硼层）相比，如果 MoB 的活性位密度较小，则可以通过增加 5 倍的表面积来弥补。
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