A simple and effective method was developed to prepare fluorescent carbon quantum dots (CQDs) for the detection of Fe3+ and Cu2+ in aqueous solution. The water-soluble CQDs with the diameter around 2–5 nm were synthesized using anthracite coal as the precursor. In addition, the as-prepared CQDs exhibits sensitive detection properties for Fe3+ and Cu2+ metal cations with a detection limit of 18.4 nM and 15.6 nM, respectively, indicating that the coal-derived CQDs sensor is superior for heavy metal recognition and environmental monitoring.

Coal-derived fluorescent carbon quantum dots for sensitive and selective detection of Cu2+ and Fe3+
    Abstract
    1 Introduction
    2 Experimental methods
        2.1 Synthesis of CQDs
        2.2 Sample characterization
        2.3 Quantum yield
        2.4 Selective metal ion detection
        2.5 pH effect of on the fluorescence intensity of CQDs
        2.6 Detection of Fe3+ and Cu2+
    3 Results and discussion
    4 Conclusions
    Acknowledgements 
    References

• Xiyu Zhao(School of Chemistry and Chemical Engineering, Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Hexi University, Zhangye, Gansu, China) Corresponding author
• Yuqi Han(School of Chemistry and Chemical Engineering, Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Hexi University, Zhangye, Gansu, China)
• Xiangwen Miao(School of Chemistry and Chemical Engineering, Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Hexi University, Zhangye, Gansu, China)
• Xingmei You(School of Chemistry and Chemical Engineering, Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Hexi University, Zhangye, Gansu, China)
• Cheng Cao(School of Chemistry and Chemical Engineering, Key Laboratory of Hexi Corridor Resources Utilization of Gansu, Hexi University, Zhangye, Gansu, China)