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.

计算设计可以加速发现具有定制特性的新材料，但是将这种方法应用于直径大于几纳米的等离子纳米粒子是具有挑战性的，因为原子第一性原理对于此类系统而言是不可行的。在本文中，我们采用了最近开发的特定于材料的方法，该方法结合了有效的电子质量理论和对局部表面等离激元的准静态描述，从而确定了有前途的双金属核-壳纳米粒子，可用于热电子光催化。具体而言，我们计算了100种不同的核壳纳米粒子的热载流子生成速率，发现具有碱金属核和过渡金属壳的系统显示出高的水分解性能，并且在水性环境中稳定。我们的分析表明，这些系统的高效率与其电子结构有关，该电子结构的特征是壳体中具有二维电子气。我们的计算进一步表明，热载流子的性质是高度可调的，并且敏感地取决于核和壳的大小。由我们的工作得出的设计规则可以指导改进太阳能转换设备的实验进展。