Green Synthesis of Fluorescent Carbon Dots through Solvothermal Treatment of Buchnania lanzan Leaf Extract

Abstract

: In the present work we have synthesized fluorescent carbon dots (CDs) through solvothermal treatment of Buchnania lanzan leaves extract at 160 °C for 4 h in oven. Here, Buchnania lanzan leaves serve as a renewable source of carbon. The obtained blackish brown CDs solution was centrifuged and the supernatant was filtered through syringe filter (0.22 µm). Further, the CDs solution was dried in vacuum oven to obtain powder. The synthesized CDs were characterized by different techniques including UV-Visible spectroscopy, fluorescence spectroscopy, fourier trans-form infrared (FTIR), zeta potential, x-ray diffraction (XRD). The as prepared CDs solution was found brownish colored in day light while exhibited green fluorescence under UV light. UV-Visible absorption spectrum displayed characteristic shoulder peaks of CDs at 257 nm and at 356 nm. In the fluorescence spectra, excitation dependent emission behaviour of CDs was seen, which is one of the distinct characteristics of CDs. The negative zeta potential and characteristic peaksin FTIR, suggested presence of carbonyl, amine and hydroxyl functional groups on the CDs surface. XRD spectrum exhibited broad peak at 2θ=19°, suggesting amorphous nature of CDs similar as reported in earlier works. As we have synthesized surface functionalized fluorescent carbon dots from a renewable and abundant precursor, this method can be highly useful in large scale synthesis of carbon dots with reduced costs and will find potential applications in the field of drug delivery,