Chemical Fabrication of Efficient Blue‐luminescent Carbon Quantum Dots from Coal Washery Rejects (Waste) for Detection of Hg2+ and Cr6+ Ions in Water. Issue 14 (7th April 2022) - Boruah, Anusuya
Abstract: An economical facile method was established for the preparation of luminescent carbon quantum dots (CQDs) by utilizing the waste coal washery rejects as precursor materials. The derived CQDs were extensively characterized for their physio‐chemical properties and they (Mcqds and Dcqds) show an efficient maximum quantum yield of 11 % with an average particle size of 2.5‐3.0 nm. The derived CQDs exhibited better physical and chemical properties at maximum excitation and emission wavelengths of 360 nm and 450 nm, respectively, with blue‐light emission. The as‐synthesized CQDs (Mcqds) were applied as a fluorescent sensing probe for sensitive detection of Hg 2+ and Cr 6+ ions in water samples, showing reasonable limit of detection and quantification with recovery percentage of 96–100 %. The study has shown potential for using such cheap waste‐material derived CQDs as for further development of sensing devices in future. Abstract : The coal washery rejects are waste materials generated in coal washeries in many countries. In this piece of work, these waste materials are sustainably utilized for chemical synthesis of high‐valued carbon quantum dots (CQDs) for using in sensing of hazardous Hg 2+ and Cr 6+ ions in water. The as‐synthesized CQDs are observed to be blue‐emitting with maximum quantum yield of 11 % with promising optical and physical properties.