Abstract As a promising photocatalytic material, g-C3N4 has drawn tremendous research interest. However, the fast charge recombination and narrow range of solar absorption restrain its practical application. Herein, for the first time, based on extensive hybrid functional calculations, graphyne (Gyne), a new two dimensional material, is used to form a layered vdW-nanohybrid with g-C3N4 to enhance the photoelectrocatalytic activity of g-C3N4. A comprehensive theoretical study of interfacial properties of g-C3N4/Gyne heterostructure including the band structure, partial density of state, optical absorption, wave functions, charge density difference, band alignment and photocurrent density is acquired to provide deep insight into the photocatalytic performance. The calculated results show that g-C3N4/Gyne heterostructure exhibits tremendous photocatalytic performance as that of recently experimentally synthesized Gyne family based nanocomposite, g-C3N4/graphdiyne (g-C3N4/GDyne). The designed g-C3N4/Gyne heterostructure has a fourfold increase in photocurrent density (0.937 μA/mm2) compared with that of g-C3N4 (0.233 μA/mm2). More importantly, the photocatalytic performance of g-C3N4/Gyne can be further improved by doping 2BN-pairs into Gyne layer. Theoretical prediction indicates that g-C3N4/2BN-Gyne even realizes a sevenfold increase in photocurrent density (1.669 μA/mm2) due to the type II band alignment, broadened light absorption range and much smaller effective mass, providing helpful physical mechanism information for further optimizing the optoelectronic properties of g-C3N4/GDyne and g-C3N4/Gyne. Our theoretical work provides stepping stone into the design of highly efficient g–C3N4–based photocatalysts and a fully coherent picture about the interfaces of g-C3N4/GDyne and g-C3N4/Gyne heterostructures can also be obtained.

中文翻译：

---

通过 BN 掺杂在 g-C3N4/石墨烯异质结构中可调 I/II 型跃迁：一种有前途的光催化剂

摘要 作为一种很有前途的光催化材料，g-C3N4 引起了极大的研究兴趣。然而，快速电荷复合和太阳能吸收范围窄限制了其实际应用。在此，首次基于广泛的杂化泛函计算，使用新型二维材料石墨炔（Gyne）与 g-C3N4 形成层状 vdW-纳米杂化物，以增强 g-C3N4 的光电催化活性。对 g-C3N4/Gyne 异质结构的界面性质进行了全面的理论研究，包括能带结构、部分态密度、光吸收、波函数、电荷密度差、能带排列和光电流密度，以深入了解光催化性能。计算结果表明，g-C3N4/Gyne 异质结构表现出与最近实验合成的基于 Gyne 家族的纳米复合材料 g-C3N4/石墨炔 (g-C3N4/GDyne) 一样的巨大光催化性能。与 g-C3N4 (0.233 μA/mm2) 相比，设计的 g-C3N4/Gyne 异质结构的光电流密度 (0.937 μA/mm2) 增加了四倍。更重要的是，通过在 Gyne 层中掺杂 2BN 对，可以进一步提高 g-C3N4/Gyne 的光催化性能。理论预测表明 g-C3N4/2BN-Gyne 由于 II 型能带排列、扩大的光吸收范围和更小的有效质量，甚至实现了光电流密度的七倍增加（1.669 μA/mm2），为进一步研究提供有用的物理机制信息优化 g-C3N4/GDyne 和 g-C3N4/Gyne 的光电性能。