Pistachio shell-derived carbon dots and their screen-printing formulation for anticounterfeiting applications

In synergy with constructing a sustainable environment, facile reuse of carbon-rich biowastes as inexpensive precursors for the synthesis of value-added functional carbon dots (CDs) has garnered fruitful outcomes. Pistachio shells comprising cellulose, hemicellulose, and lignin were successfully utilized as a carbon source for the synthesis of CDs through carbonization and subsequent hydrothermal method. The methanolic fraction with desirable fluorescence in the visible region obtained after column purification of CDs was further characterized using TEM, EDS, SAED, FTIR, XPS, RS, XRD, and TCSPC techniques. The blue and green emitting CDs were used as colorants to prepare a water-based ink for screen printing. The screen prints on UV dull paper substrate exhibited good colorimetric and density values. The UV-induced yellow fluorescence of the ink film can be used as a security feature to authenticate genuine document/products and data storage.