Bai Xiaowan, Ling Chongyi, Shi Li, Ouyang Yixin, Li Qiang, Wang Jinlan
School of Physics, Southeast University, Nanjing 211189, China.
School of Physics, Southeast University, Nanjing 211189, China.
Sci Bull (Beijing). 2018 Nov 15;63(21):1397-1403. doi: 10.1016/j.scib.2018.10.006. Epub 2018 Oct 13.
MXenes have exhibited great potential as cost-effective electrocatalysts for hydrogen evolution reaction (HER). However, insight into the origin of activity is still missing. Herein, on the basis of a systematical investigation of the HER performance of 20 MXenes (MNO and MCO, M = Sc, Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W), a Fermi-abundance model is proposed to understand variation of the activity in different MXenes. It is found that the occupied p electronic states of surface O atoms play a decisive role in the HER activity of MXenes. More importantly, TiNO and NbNO are found to be promising HER electrocatalysts with the free energy for hydrogen adsorption close to zero. This work not only provides possible catalysts for HER, the developed Fermi-abundance model but also is applicable to other two-dimensional materials and may serve as a simple descriptor of the intrinsic HER activity.
MXenes作为析氢反应（HER）具有成本效益的电催化剂已展现出巨大潜力。然而，对活性起源的深入了解仍然缺失。在此，基于对20种MXenes（MNO和MCO，M = Sc、Ti、V、Cr、Zr、Nb、Mo、Hf、Ta和W）析氢反应性能的系统研究，提出了一种费米丰度模型来理解不同MXenes中活性的变化。研究发现，表面O原子的占据p电子态在MXenes的析氢反应活性中起决定性作用。更重要的是，发现TiNO和NbNO是有前景的析氢反应电催化剂，其氢吸附自由能接近零。这项工作不仅为析氢反应提供了可能的催化剂，所开发的费米丰度模型还适用于其他二维材料，并可作为析氢反应固有活性的简单描述符。
