Review of Carbon Dots from Lignin: Preparing, Tuning, and Applying

keywords:lignin  carbon dots  fluorescence tuning  sensing  supercapacitor  bioimaging

Abstract:Carbon dots (CDs), emerging carbon materials with unique physical and chemical properties, have drawn extensive attention from researchers. In recent years, many carbon sources have been used as precursors for preparing CDs. In contrast to other types of precursors, lignin, as a renewable and available source of natural aromatic biopolymers, is believed to be a low-cost precursor for the large-scale preparation of CDs. However, the preparation of CDs with excellent optical properties from lignin has some drawbacks because of the complex structure of lignin. Hence, the methods for preparing the CDs from lignin are summarized in this paper, and the mechanism and physical and chemical properties of lignin-based CDs are discussed. Moreover, some approaches to tuning the optical properties of lignin-based CDs have been proposed. Additionally, the use of lignin-based CDs in the fields of sensing, supercapacitor, bioimaging, anti-counterfeiting, and information encryption is reviewed.