Recyclable luminescent carbon dots nanopaper for flexible electronics

The use of sustainable materials in high-tech devices is one way to decrease the carbon footprint and tackle global climate change. We first synthesized blue-emissive carbon dots (CDs) from biocompatible onion inner epidermal cells using solvothermal method. Then, cellulose nanofiber was prepared by TEMPO oxidization, followed by homogenization from soft wood source. Finally, the blue emissive CDs-cellulose nanofibers-based nanopaper was fabricated by simple roller-coating approach, and its optical and morphological properties were investigated by transmittance, photoluminescence, fourier-transform infrared (FTIR) and scanning electron microscopy techniques. The results indicate that nanopapers have a high light emission, and that their transparency may be easily adjusted by varying the proportion of CDs content. These nanopapers can be incorporated into flexible and stretchable electronics and optical sensor platforms.