npj: 双金属核壳纳米粒子——热载流子光催化计算设计

海归学者发起的公益学术平台

分享信息，整合资源

交流学术，偶尔风月

人们希望计算设计可用来促进具有定制特性的新材料发现，但是将计算设计用于直径大于几纳米的等离子体纳米颗粒，却颇有挑战性，因为原子级第一性原理计算不适用于这样的系统。

来自英国伦敦帝国理工学院的Luigi Ranno教授等进行了一项理论研究，他们将电子的有效质量理论与局部表面等离子体的准静态描述相结合，便可计算来自数百个核-壳纳米颗粒的热载流子产生速率，确定其为光催化应用的最佳候选物，能在水环境中保持稳定，满足有效裂解水的关键要求。他们的分析表明，这些系统的高效率与它们的电子结构具有二维电子气有关。不仅如此，他们还发现依据核和壳的尺寸在宽泛的范围内可对热载流子性质进行调控。值得注意的是，具有碱金属核和过渡金属壳的双金属纳米颗粒，在增强的热载流子产生速率和水分解能力方面，提供了最高的品质因数。

该文近期发表于npj Computational Materials 4: 31 (2018)  ，英文标题与摘要如下，点击左下角“阅读原文”可以自由获取论文PDF。

Computational design of bimetallic core-shell nanoparticles for hot-carrier photocatalysis 

Luigi Ranno, Stefano Dal Forno & Johannes Lischner 

Computational design can accelerate the discovery of new materials with tailored properties, but applying this approach to plasmonic nanoparticles with diameters larger than a few nanometers is challenging as atomistic first-principles calculations are not feasible for such systems. In this paper, we employ a recently developed material-specific approach that combines effective mass theory for electrons with a quasistatic description of the localized surface plasmon to identify promising bimetallic core-shell nanoparticles for hot-electron photocatalysis. Specifically, we calculate hot-carrier generation rates of 100 different core-shell nanoparticles and find that systems with an alkali-metal core and a transition-metal shell exhibit high figures of merit for water splitting and are stable in aqueous environments. Our analysis reveals that the high efficiency of these systems is related to their electronic structure, which features a two-dimensional electron gas in the shell. Our calculations further demonstrate that hot-carrier properties are highly tunable and depend sensitively on core and shell sizes. The design rules resulting from our work can guide experimental progress towards improved solar energy conversion devices.

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