Lin Jiahe, Zhang Bofeng
School of Science, Jimei University, Xiamen, 361021, China.
Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
Phys Chem Chem Phys. 2024 Mar 13;26(11):8982-8992. doi: 10.1039/d3cp06143d.
Metal-free two-dimensional (2D) semiconductors have garnered significant attention in the realm of photocatalytic water splitting, primarily owing to their inherent clean, stable, and efficient photoresponsive properties. Motivated by it, we have proposed two types of stable CP monolayers with indirect band gaps, mediocre carrier mobility and excellent optical absorption in visible-light and ultraviolet regions. Although the too-low work function of monolayer α-CP and the too-high work function of monolayer β-CP make them only suitable for single-side redox reaction in photocatalytic water splitting, the creation of an α-CP/β-CP Z-scheme heterojunction, combined with the Janus monolayer γ-CP that integrates features of both α and β structures, effectively addresses this limitation, fulfilling the prerequisites for comprehensive photocatalytic water splitting. Furthermore, the calculations indicate that the α-CP/β-CP Z-scheme heterojunction and Janus monolayer γ-CP not only demonstrate improved carrier mobility and optical absorption but also feature internal electric fields that effectively enhance driving energy and photo-induced charge separation. Notably, Janus monolayer γ-CP achieves a high electron mobility of ∼10 cm V s and an impressive solar-to-hydrogen conversion efficiency of 25.62%.
无金属二维（2D）半导体在光催化水分解领域引起了广泛关注，主要是由于其固有的清洁、稳定和高效的光响应特性。受此启发，我们提出了两种具有间接带隙、中等载流子迁移率以及在可见光和紫外区域具有优异光吸收性能的稳定CP单层。尽管单层α-CP的功函数过低以及单层β-CP的功函数过高，使得它们仅适用于光催化水分解中的单侧氧化还原反应，但α-CP/β-CP Z型异质结的创建，结合了兼具α和β结构特征的双面单层γ-CP，有效解决了这一限制，满足了全面光催化水分解的先决条件。此外，计算表明，α-CP/β-CP Z型异质结和双面单层γ-CP不仅表现出提高的载流子迁移率和光吸收，还具有有效增强驱动能量和光生电荷分离的内建电场。值得注意的是，双面单层γ-CP实现了约10 cm V s的高电子迁移率以及令人印象深刻的25.62%的太阳能到氢能转换效率。
