Semiconductor photocatalyst mediated advanced oxidation processes are regarded as one of the most efficient technologies to mitigate organic pollutants in water. However, poor activity under visible light and the recombination of photogenerated electron and hole pairs hinder large scale applicability of semiconductor photocatalysts for water purification. The modification of semiconductor photocatalysts with carbon quantum dots (CQDs) is of high importance due to low toxicity, aqueous stability, enhanced surface area, economic feasibility, good biocompatibility and chemical inertness of CQDs. In this review, we highlight strategies to improve the activity of conventional semiconductor photocatalysts via coupling with CQDs. The enhanced photocatalytic activity of CQD modified narrow and wide band gap photocatalysts is due mainly to up-conversion photoluminescence (UPCL) and the electron reservoir properties of CQDs, while in the case of Z-scheme photocatalysts CQDs act as an electron mediator. Finally, a conclusive outlook and suggested research directions are provided to address challenges such as the inadequate separation of photoinduced charge carriers.

半导体光催化剂介导的高级氧化过程被认为是减轻水中有机污染物的最有效技术之一。然而，可见光下的不良活性以及光生电子和空穴对的复合阻碍了半导体光催化剂在水净化中的大规模应用。由于碳量子点（CQD）的低毒性，水稳定性，表面积增加，经济可行性，良好的生物相容性和化学惰性，因此用碳量子点（CQD）改性半导体光催化剂具有重要意义。在这次审查中，我们强调战略，以改善现有的半导体光催化剂的活性，通过与CQD耦合。CQD修饰的窄带和宽带隙光催化剂的增强的光催化活性主要是由于上转换光致发光（UPCL）和CQD的电子储库性能，而在Z型光催化剂的情况下，CQD充当电子介体。最后，提供了结论性的观点和建议的研究方向，以解决诸如光诱导电荷载流子分离不充分的挑战。