Feng Shuang, Miao Nanxi, Wang Junjie
School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, People's Republic of China.
ACS Appl Mater Interfaces. 2021 Dec 1;13(47):56131-56139. doi: 10.1021/acsami.1c16449. Epub 2021 Nov 18.
Hexagonal MAB (-MAB) phases and their two-dimensional (2-D) derivatives (-MBenes) have emerged as promising materials since the discovery of TiInB. Herein, we identified that a possible -MBene, 2-D HfBO, can be an excellent platform for the electrocatalysis of hydrogen evolution reaction (HER) by density functional theory calculations. We proposed two approaches of transition metal (TM) modifications by atom deposition and implanting to optimize the HER performance of 2-D HfBO. It is revealed that a moderate charge reduction of surface O, which is induced by the introduction of TM atoms, is conductive to a higher catalytic performance. The synergistic effect between implanted TM atoms and HfBO matrix can efficiently activate the surface by broadening O-p orbitals and shifting up p-band center, especially for V, Cr, and Mo as dopants, which can reduce the Gibbs free energy (Δ) from 0.939 to -0.04, 0.05 and -0.04 eV, respectively. Interestingly, this effect works within a local region and the activity can also be evaluated by bond length of Hf-O, in addition to Δ. This work suggests that due to its excellent electrocatalysis properties, -MBenes can open up a new area for 2-D materials and will stimulate researchers to explore the synthesis of -MAB phases and the stripping of -MBenes.
自从发现TiInB以来，六方MAB（-MAB）相及其二维（2-D）衍生物（-MBenes）已成为有前景的材料。在此，我们通过密度泛函理论计算确定，一种可能的-MBene，二维HfBO，可成为析氢反应（HER）电催化的优异平台。我们提出了通过原子沉积和注入过渡金属（TM）的两种方法来优化二维HfBO的HER性能。结果表明，由TM原子引入引起的表面O适度电荷减少有利于提高催化性能。注入的TM原子与HfBO基体之间的协同效应可通过拓宽O-p轨道和上移p带中心来有效激活表面，特别是对于作为掺杂剂的V、Cr和Mo，它们可分别将吉布斯自由能（Δ）从0.939降低到-0.04、0.05和-0.04 eV。有趣的是，这种效应在局部区域起作用，除了Δ之外，还可以通过Hf-O键长来评估活性。这项工作表明，由于其优异的电催化性能，-MBenes可为二维材料开辟一个新领域，并将激发研究人员探索-MAB相的合成和-MBenes的剥离。
