Recently, two-dimensional (2D) materials with a pentagonal structure have attracted great interest since the discovery of penta-graphene, due to their unique structures and remarkable physical properties. In this work, the geometric structure, stability, electronic and optical properties and photocatalytic performances of p-SiXY₄ (X = Si, C, Ge; Y = C, B, N) pentagonal materials were systematically examined using first-principles calculations. By assessing the stability, we have found that six of the nine studied p-SiXY₄ 2D materials have excellent energetic, dynamic, and thermal stability. Electronic structures reveal that these six monolayers have a semiconductor state, with indirect band gaps ranging from 1.39 to 5.45 eV depending on the functional used, which covers the visible-ultraviolet regions. Furthermore, the band edge positions of these pentagonal monolayers perfectly meet the redox potentials for photocatalytic water splitting. The calculated optical absorption showed that p-Si₂N₄, p-SiCN₄ and p-SiGeN₄ monolayers exhibit substantial optical absorption in the ultraviolet (UV) range, whereas p-Si₂C₄, p-SiGeC₄, and p-SiCC₄ monolayers show a very high optical absorption in the visible and ultraviolet regions (up to 10⁻⁵ cm⁻¹). Our finding provides a route to design new Si-based 2D pentagonal materials with excellent application prospects such as in photocatalytic water splitting and optoelectronics.

中文翻译：

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三元五方p-SiXY4（X = Si，C，Ge；Y = C，B，N）材料在光电和光催化水分解方面的潜在应用：第一性原理研究

近年来，自五角石墨烯发现以来，具有五边形结构的二维（2D）材料因其独特的结构和卓越的物理性能而引起了人们的极大兴趣。_{在这项工作中，利用第一性原理计算系统地研究了p-SiXY 4} (X = Si, C, Ge; Y = C, B, N)五边形材料的几何结构、稳定性、电子和光学性质以及光催化性能。通过评估稳定性，我们发现九种研究的 p-SiXY ₄ 2D 材料中有六种具有优异的能量、动态和热稳定性。电子结构表明，这六个单层具有半导体态，间接带隙范围为 1.39 至 5.45 eV，具体取决于所使用的功能，涵盖可见光-紫外区域。此外，这些五边形单层的带边缘位置完全满足光催化水分解的氧化还原电位。计算的光吸收表明，p-Si ₂ N ₄、p-SiCN ₄和 p-SiGeN ₄单层在紫外 (UV) 范围内表现出大量的光吸收，而 p-Si ₂ C ₄、p-SiGeC ₄和 p -SiCC ₄单层在可见光和紫外区域（高达10 ^-5 cm ^-1）表现出非常高的光学吸收。我们的发现为设计新型硅基二维五边形材料提供了一条途径，该材料在光催化水分解和光电子学等领域具有良好的应用前景。