Hydrothermal Synthesis of Carbon Quantum Dots: An Updated Review

Abstract

Carbon Quantum Dots (CQDs) have exceptionally solid and tuneable fluorescence properties which empower their application in vast fields. The hydrothermal approach is regarded as direct and efficient, through polymerization and carbonization reactions, and has been widely applied to prepare various materials due to the high reactivity of the reactants, easy control of the solution, little harm to the environment and low energy consumption under hydrothermal condition. The attracting feature of this route is that neither any strong acid nor post-synthetic surface passivation is necessary. As of now, a lot of important progress in the hydrothermal synthesis of carbon quantum dots such as materials use as precursors and influence of hydrothermal synthesis parameters. Hydrothermal synthesis is one of the most commonly used methods for preparation of nanomaterials. It is basically a solution reaction-based approach. In this review, the main focus is to review the hydrothermal route for carbon quantum dots using different source of materials and their fundamental characterizations, followed by the influence of hydrothermal synthesis conditions to carbon quantum dots.

Carbon Quantum Dots: Properties, Preparation, and Applications

“…The hydrothermal preparation of carbon quantum dots is relatively simple and easy to achieve high QY and does not require expensive equipment. However, the preparation of CDs by hydrothermal techniques in the production of CQDs with varying surface morphology and less controllable sizes has led researchers to explore possible solutions to overcome this shortcoming [19,76,77]. Zhang et al [78] were the first to use the hydrothermal method to prepare carbon quantum dots.…”

Nano-Food Farming: Toward Sustainable Applications of Proteins, Mushrooms, Nano-Nutrients, and Nanofibers

“…They have attracted considerable attention due to their fluorescence, antimicrobial properties [152], and easy preparation [153]. They can be synthesized from mushroom extracts through hydrothermal synthesis [152,154,155] by reacting with precursor substances in a high-temperature and high-pressure aqueous environment [135,156]. The production of synthesized silver (Ag-NPs) and gold (Au-NPs) nanoparticles by microorganisms is an emerging field of nanobiotechnology, which offers a cost-effective, rapid, and environmentally friendly green chemistry method [136].…”

“…Several edible mushrooms have been explored for their ability to reduce metal ions and facilitate the formation of stable metal nanoparticles [157,158]. Fungi like Agaricus [153,154], Ganoderma [155,156], Inonotus [157,158], Pleurotus [142,143], and Schizophyllum [144,145] species have been used in the biosynthesis of silver and gold nanoparticles. The process involves the use of fungal extracts or biomass to achieve the reduction of metal ions to their respective nanoparticles.…”