Two-dimensional (2D) transition metal dichalcogenides (TMDCs) are emerging as promising building blocks of high-performance photocatalysts for visible-light-driven water splitting because of their unique physical, chemical, electronic, and optical properties. This review focuses on the fundamentals of 2D TMDC-based mixed-dimensional heterostructures and their unique properties as visible-light-driven photocatalysts from the perspective of dimensionality and interface engineering. First, we discuss the approaches and advantages of surface modification and functionalization of 2D TMDCs for photocatalytic water splitting under visible-light illumination. We then classify the strategies for improving the photocatalytic activity of 2D TMDCs via combination with various low-dimensional nanomaterials to form mixed-dimensional heterostructures. Further, we highlight recent advances in the use of these mixed-dimensional heterostructures as high-efficiency visible-light-driven photocatalysts, particularly focusing on synthesis routes, modification approaches, and physiochemical mechanisms for improving their photoactivity. Finally, we provide our perspectives on future opportunities and challenges in promoting real-world photocatalytic applications of 2D TMDC-based heterostructures.

二维（2D）过渡金属二硫化碳（TMDC）由于其独特的物理，化学，电子和光学特性，正成为有前途的高性能光催化剂的组成部分，用于可见光驱动的水分解。这篇综述着重从二维和界面工程的角度研究了基于二维TMDC的混合异质结构的基本原理及其作为可见光驱动的光催化剂的独特性能。首先，我们讨论了2D TMDC在可见光照射下进行光催化水分解的表面改性和功能化的方法和优点。然后，我们通过与各种低维纳米材料结合形成混合维异质结构，对提高2D TMDCs的光催化活性的策略进行了分类。进一步，我们重点介绍了将这些混合尺寸的异质结构用作高效可见光驱动的光催化剂的最新进展，尤其着重于合成路线，修饰方法和改善其光活性的理化机理。最后，我们对促进基于2D TMDC的异质结构在现实世界中的光催化应用的未来机遇和挑战提供了看法。