论文标题
由于拓扑极化引起的有效氢进化反应
Efficient hydrogen evolution reaction due to topological polarization
论文作者
论文摘要
携带拓扑表面状态（TSS）的材料为氢进化反应（HER）提供了一个引人入胜的平台。基于$ a_3 b $的系统性第一原理计算（$ a $ = ni，pd，pt； $ b $ = si，ge，sn），我们建议以Zak相为特征的拓扑电化极化对于为HE设计有效的催化剂至关重要。对于$ a_3 b $，我们表明Zak阶段在整个（111）投影的Brillouin区域中的非平凡价值为$π$，该区域在表面上导致量化的电动极化电荷。在那里，根据吸附位点，氢（H）原子与TSS杂交，而不是与散装状态杂交。当杂交在共价键和离子键之间具有中间特征时，H状态位于能谱中，并且由于H的吸附而引起的Gibbs自由能（$ΔG$）的变化变得很小。也就是说，H州与底物之间的相互作用变得相当虚弱，这对她来说是一个非常有利的情况。值得注意的是，我们表明PT $ _3 $ SN和PD $ _3 $ SN的$ΔG$分别仅为-0.066和-0.092 eV，几乎是PT值的一半。
Materials carrying topological surface states (TSS) provide a fascinating platform for the hydrogen evolution reaction (HER). Based on systematic first-principles calculations for $A_3 B$ ($A$ = Ni, Pd, Pt; $B$ = Si, Ge, Sn), we propose that topological electric polarization characterized by the Zak phase can be crucial to designing efficient catalysts for the HER. For $A_3 B$, we show that the Zak phase takes a nontrivial value of $π$ in the whole (111) projected Brillouin zone, which causes quantized electric polarization charge at the surface. There, depending on the adsorption sites, the hydrogen (H) atom hybridizes with the TSS rather than with the bulk states. When the hybridization has an intermediate character between the covalent and ionic bond, the H states are localized in the energy spectrum, and the change in the Gibbs free energy ($ΔG$) due to the H adsorption becomes small. Namely, the interaction between the H states and the substrate becomes considerably weak, which is a highly favorable situation for the HER. Notably, we show that $ΔG$ for Pt$_3$Sn and Pd$_3$Sn are just -0.066 and -0.092 eV, respectively, which are almost half of the value of Pt.
