Black phosphorus (BP) is a promising two-dimensional (2D) semiconductor, because of its tunable band gap and high hole mobility; however, its easy degradation under atmospheric conditions largely limits its application in photocatalytic water-splitting reactions. To overcome this disadvantage, we proposed a strategy for designing sandwiched P₄O₂-encapsulated BP (P₄O₂/BP) 2D materials, considering the automatic formation and high stability of P₄O₂ in air. We systematically considered five different packing models involving twenty sandwiched P₄O₂/BP systems using first-principles calculations. Through the triple screening process of 20 sandwiched P₄O₂/BP systems, we found that the O-1-P system with intrinsic electric field ingeniously combines all the desired features for photocatalytic water-splitting reactions, including small direct band gap (1.34 eV), low exciton binding energy, high hole mobility and ultrahigh solar-to-hydrogen efficiency as high as 22.77%. Through Gibbs free energy calculations, the active sites and possible reaction pathways of full water-splitting reactions were also confirmed. Our work offers useful guidance for designing and fabricating stable 2D materials with high performance for application in photocatalytic water-splitting reactions.

中文翻译：

---

具有稳定的P4O2 /黑磷夹心异质结构和高的太阳能转化效率的光解水反应光催化剂

黑磷（BP）由于其可调节的带隙和高空穴迁移率而成为一种有前途的二维（2D）半导体。但是，它在大气条件下容易降解，大大限制了其在光催化水分解反应中的应用。为了克服这个缺点，考虑到P ₄ O ₂在空气中的自动形成和高稳定性，我们提出了一种设计策略，用于设计夹心P ₄ O ₂包裹的BP（P ₄ O ₂ / BP）2D材料。我们系统地考虑了五种不同的包装模型，涉及二十种夹心P ₄ O ₂/ BP系统使用第一性原理计算。通过20个夹心P ₄ O ₂ / BP系统的三重筛选过程，我们发现具有固有电场的O-1-P系统巧妙地结合了光催化水分解反应的所有所需功能，包括小的直接带隙（1.34 eV），低激子结合能，高空穴迁移率和超高的太阳能对氢效率高达22.77％。通过吉布斯自由能计算，也证实了完全水分解反应的活性位点和可能的反应途径。我们的工作为设计和制造用于光催化水分解反应的高性能2D材料提供了有用的指导。