UNIVERSAL METHOD FOR PREPARATION OF METAL-DOPED CARBON QUANTUM DOTS

Abstract

Carbon quantum dots (CQDs) have been drawn much attention for diverse application due to their low toxicity, excellent biocompatibility, visible photoluminescence and easy synthesis. Doping CQDs with metal ions has been demonstrated to add functionalities such as catalytic and magnetic properties for photocatalysis, bio-imaging and bioanalytic applications. Herein, we repot a universal method for preparation of metal doped CQDs (M-CQDs, M= Cu²⁺, Fe³⁺, Mn²⁺ and Pb²⁺). The universary is enabled by using complexes of the metal ions with ethylenediaminetetraacetic acid (EDTA) as single precursor. The mass fraction of metal varied from 3 to 13% as determined by atomic absoption spectroscopy. Optical properties of CQDs and M-CQDs were studied by UV-Vis absorption and photoluminescence spectroscopy. Metal ions such as Fe³⁺, Pb²⁺ and Cu⁺² change the absorption profile in the UV region and while the emission quantum yield of QDs varied from 6 to 27%. The method is of importance for preparation of a series of M-CQDs from which the effects of metal ions on the properties of CQDs can be revealed.