One-pot hydrothermal synthesis and characterization of carbon quantum dots (CQDs)

Carbon quantum dots (CQDs) have emerged as the promising class of fluorescent nanomaterials with size ranging from 2 to 10 nm. The CQDs possess amazing properties such as good solubility, photoluminescence, high quantum yield, functional groups on surface, photostability, biocompatibility and low toxicity. CQDs are a trending topic of intense research as they are being used for a wide range of applications such as biological imaging, sensing, drug delivery and catalysis. Nowadays, the focus of researchers has shifted towards the green synthesis of CQDs from natural and environment friendly sources. The present work reports the synthesis of fluorescent CQDs from cabbage as the natural carbon source by hydrothermal method. The as-synthesized CQDs were characterized using various analytical techniques to obtain information regarding their absorption/emission spectra, chemical functionality and morphology. Further, the synthesized CQDs were explored for optical sensing of various heavy metal ions in aqueous medium. The study provides a simple and economical method of utilizing CQDs for environmental sensing applications.