An Introduction to Carbon Quantum Dots

Carbon quantum dots (CQDs), a novel family of carbon dots (CDs) are one of the emerging materials among several carbon-based nano-ranged materials. They have attained much interest and become a profound competitor to traditional semiconductor quantum dots for several applications. Since their discovery, CQDs are widely used for several applications like chemical sensing, bioimaging, biosensing, drug delivery, photocatalysis because of several characteristics associated with them such as tiny sizes (<10 nm), low toxicity, bio-compatibility, optical properties, water solubility, photocatalytic properties, ease of surface modifications, simple and eco-friendly synthesis routes by making usage of waste biomass that ultimately made the process cost-effective. Methods widely used for synthesis purpose are hydrothermal, microwave, ultrasonication, laser ablation, and pyrolysis among which hydrothermal is more common. Green CQDs are basically CDs synthesised by making usage of biomass. Availability and abundance of biomass makes the process eco-friendly and cost effective by providing a variety of precursors. Along with, these materials are becoming promising candidates for environmental applications such as sensing and absorption of toxic metal ions, water remediation through degradation of harsh textile effluents. This chapter provides the basic details regarding the material including synthesis, properties and basic applications.