Developing two-dimensional heterojunctions is an excellent approach to achieve exceptional optical, electrical, and photocatalytic properties. Here, we used the periodic density functional theory simulations to engineer the electronic band structure, charge separation efficiency, as well as the photocatalytic properties of g-C₃N₄ and B₄C₃ based two-dimensional van der Waals heterojunctions. The effect of strain on the band edge energy and band structure was investigated in detail. The effective mass of electrons (m_e*/m_о = 0.76) and holes (m_h*/m_о = 1.16) in the B₄C₃/g-C₃N₄ heterojunction predicted a superior mobility than in isolated g-C₃N₄ monolayer (m_e* = 0.98; m_h* = 1.34). The ΔG_H* value (-0.10 eV) of the atomic hydrogen on B₄C₃/g-C₃N₄ heterojunction confirmed the superior HER performance in contrast to isolated g-C₃N₄ (ΔG_H* =0.108 eV) and B₄C₃ (ΔG_H* = -0.22 eV) monolayers. Our study offers possibilities to produce a novel B₄C₃/g-C₃N₄ heterojunction for the photocatalytic water splitting and optoelectrical applications.

开发二维异质结是获得优异的光学，电学和光催化性能的绝佳方法。在这里，我们使用周期密度泛函理论模拟来设计电子带结构，电荷分离效率以及基于g -C ₃ N ₄和B ₄ C ₃的二维范德华异质结的光催化性能。详细研究了应变对能带边能量和能带结构的影响。 B ₄中电子的有效质量（m _e * / _mо  = 0.76）和空穴（m _h * / _mо = 1.16）与孤立的g -C ₃ N ₄单层相比，C ₃ / g -C ₃ N ₄异质结预测的迁移率更高（m _e * = 0.98； m _h * = 1.34）。B ₄ C ₃ / g -C ₃ N ₄异质结上氢原子的ΔGH _*值（-0.10 eV）与孤立的g -C ₃ N ₄（ΔGH _* = 0.108 eV）相比，证实了优异的HER性能。和B ₄ C ₃（ΔG_{H *} = -0.22 eV）单层。我们的研究提供了为光催化水分解和光电应用生产新型B ₄ C ₃ / g -C ₃ N ₄异质结的可能性。