Pyrolysis Synthesis of Monodispersed Carbon Quantum Dots from Pomegranate Husk

Abstract

Carbon Quantum Dots (CQDs) are a remarkable class of nanocarbon materials with average particle size below 10 nm. They have good photoluminescence properties, and they can be easily synthesized from natural biomass through simple synthesis routes like hydrothermal and thermal decomposition of organic matter. The biocompatibility and the simplicity of the synthesis process make this class of materials a high candidate to replace the highly toxic semiconductor quantum dots. This study details the preparation of CQDs using pomegranate husk via a simple pyrolysis synthesis route. The optical, morphological, and structural characteristics of the synthesized CQDs were investigated using UV-vis absorption spectrophotometry, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD), respectively. Also, FTIR spectroscopy was measured to study the function groups attached to the CQDs. TEM analysis confirmed the presence of nearly spherical dot particles with a narrow size distribution, yielding an average diameter of 6.2 nm. The optical characterization revealed that the obtained CQDs exhibit fluorescence with maximum emission at 450 nm, and notably, the fluorescence emission maxima was observed to shift towards higher wavelengths (red shift) with excitation wavelength.