Carbon dots-based nanocomposites for heterogeneous photocatalysis.

• Photocatalytic mechanism of carbon dots/nanomaterial system is discussed. • Four typical carbon dots-synergistic enhancement effects are highlighted. • Summary of carbon dots-based nanocomposites with the synergistic effect. • Application of carbon dots-based nanocomposite photocatalysts. Carbon dots (CDs), as a class of promising and multifunctional carbon nanomaterials, have become a research hotspot in the field of photocatalysis owning to strong absorption of visible light, favorable photoelectric properties, and tunable energy-level configuration. Although numerous efforts have been made to improve photocatalytic performance by combining CDs with other semiconductors in recent years, the summary of enhancement mechanisms for this emerging technology is few reported. Fully understanding the synergistic effect of CDs and nanomaterials in photocatalytic applications is extremely important for the further development of photocatalysis in the future. Here, the photocatalytic mechanism of carbon dots/nanomaterial system is discussed. Four typical carbon dots-synergistic enhancement effects are highlighted, namely, energy band regulation, local electric construction, active site engineering, and multiple carrier activation. Second, the recent progress of carbon dots-based nanocomposites in efficient solar energy conversion is reviewed and examples are given. Finally, the future research development direction and challenges are emphasized on this basis. In this review, the mechanism of CDs enhanced photocatalysis in CDs-based nanocomposites for photocatalytic applications is summarized. [Display omitted] [ABSTRACT FROM AUTHOR]