Silicene is a relatively new member of the growing family of two-dimensional single-element materials. Both top-down and bottom-up approaches provide access to silicene, the former via vapor deposition on a substrate and the latter via exfoliation of the layered CaSi₂ precursor. Most top-down research has been concerned with understanding the various electronic, optical, magnetic, mechanical, electrical, thermal transport and gas-adsorption properties of silicene. By contrast, the focus on bottom-up silicene has primarily been on its synthesis, structure and chemical properties as they relate to its function and utility. Herein, emphasis is placed on the bottom-up strategy because of its scalability and the ease of subsequent silicene modification, with both qualities being important prerequisites for heterogeneous catalysis applications. In this context, synthetic freestanding silicene exists as single sheets or multilayer assemblies, depending on the CaSi₂ exfoliation synthesis conditions. The structure of a sheet comprises three connected chair-configuration silicon 6-rings. This connectivity creates buckled sheets in which the hybridization around the unsaturated silicon atoms is sp²–sp³. By adjusting the CaSi₂ exfoliation synthesis conditions, either layered silane (Si₆H₆) or siloxene (Si₆H₃(OH)₃) nanosheets can be obtained. In our studies, we have explored the nucleation and growth of different transition metal nanoparticles on and within the layer spaces of these nanosheets, and explored their thermochemical and photochemical reactivity in CO₂ hydrogenation reactions. An overview of these findings, related works and a new-and-optimized catalyst are provided in this article.

中文翻译：

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硅纳米结构的下一件大事-CO2光催化。

硅树脂是二维单元素材料家族中一个相对较新的成员。自上而下和自下而上的方法都可以访问硅，前者通过气相沉积在基板上，而后者则通过分层CaSi _2的剥离来实现。前体。大多数自上而下的研究都与理解硅的各种电子，光学，磁性，机械，电气，热传输和气体吸附特性有关。相比之下，对自下而上的硅的关注主要在于其合成，结构和化学性质，因为它们与其功能和效用有关。这里，由于其可扩展性和随后的硅改​​性的容易性，因此将重点放在自下而上的策略上，这两种性质是非均相催化应用的重要先决条件。在这种情况下，合成的独立式的硅烯存在作为单个片材或多层组件，这取决于硅钙₂剥落的合成条件。片的结构包括三个相连的椅子构形的硅6环。这种连通性产生了弯曲的薄片，其中围绕不饱和硅原子的杂化是sp ² –sp ³。通过调节CaSi ₂剥离合成条件，可以获得层状硅烷（Si ₆ H ₆）或硅氧烷（Si ₆ H ₃（OH）₃）纳米片。在我们的研究中，我们探索了在这些纳米片的层空间之上和之内的不同过渡金属纳米粒子的形核和生长，并探索了它们在CO _2中的热化学和光化学反应性氢化反应。本文提供了这些发现的概述，相关工作以及一种新的和优化的催化剂。