Sustainable Synthesis of Bright Green Fluorescent Nitrogen‐Doped Carbon Quantum Dots from Alkali Lignin

Abstract Sustainable, inexpensive, and environmentally friendly biomass waste can be exploited for large‐scale production of carbon nanomaterials. Here, alkali lignin was employed as a precursor to synthesize carbon quantum dots (CQDs) with bright green fluorescence through a simple one‐pot route. The prepared CQDs had a size of 1.5–3.5 nm, were water‐dispersible, and showed wonderful biocompatibility, in addition to their excellent photoluminescence and electrocatalysis properties. These high‐quality CQDs could be used in a wide range of applications such as metal‐ion detection, cell imaging, and electrocatalysis. The wide range of biomass lignin feedstocks provide a green, low‐cost, and viable strategy for producing high‐quality fluorescent CQDs and enable the conversion of biomass waste into high‐value products that promote sustainable development of the economy and human society.