Carbon quantum dots derived from waste acorn cups and its application as an ultraviolet absorbent for polyvinyl alcohol film

Extracting effective ultraviolet (UV) absorbent from biomass-based material is urgent for the sustainable development. Here, non-doped CQDs (1-CQDs) and nitrogen-doped CQDs (2-CQDs) were synthesized from acorn cups (ACs) with a green method. The active surface groups of 1-CQDs (4.16 nm) include Ph-OH, OH, and COOH, etc., while for 2-CQDs (5.23 nm), nitrogen doping provides a large number of nitrogen atoms, so that the active functional groups...