Influence of photon reabsorption on the optical and catalytic properties of carbon nanodots/titanium oxide composites

To enhance the optical and catalytic properties of TiO₂, carbon nanodots (CNDs) are incorporated to prepare hybrid CNDs/TiO₂ materials with different precursor concentrations and the photocatalytic characteristics are evaluated systematically. When the CNDs/TiO₂ materials are excited optically, some high-energy photons are reabsorbed by those in the lower energy states, indicating that photon reabsorption of CNDs plays a key role. The results enrich our understanding of the optical and catalytic mechanisms and provide insight into the design of CNDs-based composites.