Photocatalytic removal of pharmaceutical water pollutants by TiO2 – Carbon dots nanocomposites: A review

• Published in: Chemosphere (Oxford) 2022-08, Vol.301, p.134731-134731, Article 134731
• Main Authors: Sendão, Ricardo M.S., Esteves da Silva, Joaquim C.G., Pinto da Silva, Luís
• Format: Article
• Language: English
• Subjects: Aquatic pharmaceutics products; Carbon dots; Nanocomposites; Pharmaceuticals; Photocatalysis; TiO2
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.134731

Pharmaceuticals are becoming increasingly more relevant water contaminants, with photocatalysts (such as TiO2) being a promising approach to remove these compounds from water. However, TiO2 has poor sunlight-harvesting capacity, low photonic efficiency, and poor adsorption towards organic pollutants. One of the emerging strategies to enhance the photocatalytic performance of TiO2 is by conjugating it with fluorescent carbon dots. Herein, we performed a critical review of the development of TiO2 – carbon dots nanocomposites for the photocatalytic removal of pharmaceuticals. We found that carbon dots can improve the photocatalytic efficiency of the resulting nanocomposites, mostly due to increasing the adsorption of organic pollutants and enhancing the absorption in the visible range. However, while this approach shows significant promise, we also identified and discussed several aspects that need to be addressed before this strategy could be more widely used. We hope that this review can guide future studies aiming to the development of enhanced photocatalytic TiO2 – carbon dots nanocomposites. [Display omitted] •Pharmaceuticals are contaminating Earth's drinking water.•Photocatalysts, such as TiO2, may be used to photodegrade pharmaceuticals.•TiO2 is limited in terms of photonic efficiency and pollutant adsorption.•Carbon dots bridge those limitations and led to a lower TiO2's energy band gap.•TiO2/CDs nanocomposites efficiently remove pharmaceuticals from water.