Recent advances in carbon dot-driven nanomaterials for photoelectrochemical-based degradation of contaminants: A review

Carbon dots (CDs) have attracted increasing attention due to their unique physicochemical and photophysical properties, such as strong photoluminescence, high crystallinity, and excellent dispersibility. This review focuses on the synthesis, characterization, and application of CD-based nanostructures in photoelectrochemical (PEC) degradation systems for the removal of pollutants. The commonly employed synthesis methods, such as hydrothermal, solvothermal, and others, are comprehensively discussed along with their advantages, limitations, and scalability potential. In addition, the review highlights the basic principles of photoelectrochemical degradation, emphasizing the role of CDs as efficient light-harvesting and charge-transfer materials. The characterization techniques used to evaluate the structural, optical, and electronic properties of CDs are briefly summarized. Moreover, recent innovations in the design and functionalization of CD-based composites for enhanced photocatalytic activity are reviewed. Particular attention is given to degradation mechanisms, interfacial charge dynamics, and strategies for improving quantum efficiency and stability. Finally, the current challenges and research gaps are outlined, with perspectives on future directions aimed at developing sustainable, low-cost, and high-performance CD-based PEC technologies for environmental remediation.