Natural‐Product‐Derived Carbon Dots: From Natural Products to Functional Materials

Abstract

Nature provides an almost limitless supply of sources that inspire scientists to develop new materials with novel applications and less of an environmental impact. Recently, much attention has been focused on preparing natural‐product‐derived carbon dots (NCDs), because natural products have several advantages. First, natural products are renewable and have good biocompatibility. Second, natural products contain heteroatoms, which facilitate the fabrication of heteroatom‐doped NCDs without the addition of an external heteroatom source. Finally, some natural products can be used to prepare NCDs in ways that are very green and simple relative to traditional methods for the preparation of carbon dots from man‐made carbon sources. NCDs have shown tremendous potential in many fields, including biosensing, bioimaging, optoelectronics, and photocatalysis. This Review addresses recent progress in the synthesis, properties, and applications of NCDs. The challenges and future direction of research on NCD‐based materials in this booming field are also discussed.

Biomass‐Derived Carbon Dots and Their Applications

“…HTC is a carbon nanomaterial synthesis technology, which has been widely used in many fields . HTC has been used to prepare novel carbon‐based materials from biomass carbon precursors such as sweet pepper, garlic, husks of nuts, papaya juice, rice husk, and other biomass materials …”

“…BCDs are prepared from plants, animals, and microorganisms and their excreta. Due to several merits of BCDs, including their convenient synthesis, low cost, good renewability, colorful PL, and excellent biocompatibility, scientists have been inspired to develop new materials with novel applications and low environmental impact . Recently, groups have described many applications based on BCDs.…”

Manipulating the Optical Properties of Carbon Dots by Fine‐Tuning their Structural Features

“…[16,17] In addition, quantumc onfinement, [18] carbon cluster agglomeration, and the formation of supramolecular aggregates [19] have also been reported, and this demonstrates the great complexity of their optical absorption and emission properties and the need for fundamentals tudies to unlock their potential for semiconductor-like and biological applications. [21,22] In HTC, carbohydrates are converted to micrometer-sized carbonaceous spheres by ap rocess involving formation of 5-hydroxymethylfurfural, its "polymerization"b yanucleation-growth process, and intermoleculard ehydration.S imultaneously to the formation of the micrometer-sized spheres ediments in the aqueous phase, CDs with ad iameter of af ew nanometers are also formed, which have been shown to have crystalline domains despite the low carbonization temperatures. [21,22] In HTC, carbohydrates are converted to micrometer-sized carbonaceous spheres by ap rocess involving formation of 5-hydroxymethylfurfural, its "polymerization"b yanucleation-growth process, and intermoleculard ehydration.S imultaneously to the formation of the micrometer-sized spheres ediments in the aqueous phase, CDs with ad iameter of af ew nanometers are also formed, which have been shown to have crystalline domains despite the low carbonization temperatures.…”

Hydrothermal synthesis, characterization and seed germination effects of green‐emitting graphene oxide‐carbon dot composite using brown macroalgal bio‐oil as precursor

“…Carbon dots (CDs) or carbon quantum dots (CQDs) come under the category of carbon materials that are fluorescent in nature and have sizes below 10 nm . CDs have received immense attention owing to their exciting electronic, physicochemical, optical and fluorescence emission properties, as well as the possibility for further modifications, and find importance in various fields .…”