Encouraged by its excellent electronic, optical, and mechanical properties, two-dimensional nanomaterials, including graphene, germanene, silicene, phosphorene, transition metal dichalcogenides, hexagonal boron nitride and so on, have generated significant research interests in a wide range of fields. In many applications, bandgap perform an important and even decisive role. However, there are very limited works that focused on a highly comprehensive overview of bandgap engineering in two-dimensional nanomaterials. Here, we review the feasibility, methods, and effects on applications of bandgap engineering in two-dimensional nanomaterials. We first provide a brief introduction on the physical significance of bandgap in two-dimensional nanomaterials. Then, based on the effect on the structure of two-dimensional nanomaterials, we introduce several methods to control and regulate the bandgap. Thereafter, bandgap engineering in different two-dimensional nanomaterials using various methods is summarized in detail. Further, we also emphasize the optimization of application performance through bandgap engineering. Finally, the challenges and outlooks in two-dimensional nanomaterials are proposed based on the current development status and future requirements.

受其优异的电子，光学和机械性能的鼓励，二维纳米材料，包括石墨烯，锗烯，硅烯，磷烯，过渡金属二硫化碳，六方氮化硼等，引起了广泛的研究兴趣。在许多应用中，带隙起着重要甚至决定性的作用。然而，很少有工作集中在二维纳米材料中带隙工程的高度全面的概述上。在这里，我们回顾了带隙工程在二维纳米材料中的可行性，方法及其对应用的影响。我们首先简要介绍二维纳米材料中带隙的物理意义。然后，基于对二维纳米材料结构的影响，我们介绍了几种控制和调节带隙的方法。此后，详细总结了使用各种方法在不同二维纳米材料中的带隙工程。此外，我们还强调通过带隙工程优化应用程序性能。最后，根据目前的发展现状和未来需求，提出了二维纳米材料的挑战和展望。