Electrochemical synthesis of FeNx doped carbon quantum dots for sensitive detection of Cu2+ ion

Siyuan Sun, Weijie Bao, Fan Yang, Xingru Yan, Yang Sun, Ge Zhang, Wang Yang, Yongfeng Li
2021 Green Energy & Environment  
A novel strategy was developed to fabricate FeN x -doped carbon quantum dots (Fe-N-CQDs) to detect Cu 2þ ions selectively as a fluorescence probe. The Fe-N-CQDs were synthesized by an efficient electrolysis of a carbon cloth electrode, which was coated with monoatomic ironanchored nitrogen-doped carbon (Fe-N-C). The obtained Fe-N-CQDs emitted blue fluorescence and possessed a quantum yield (QY) of 7.5%. An extremely wide linear relationship between the Cu 2þ concentration and the fluorescence
more » ... the fluorescence intensity was obtained in the range from 100 nM to 1000 nM (R 2 ¼ 0.997), and the detection limit was calculated as 59 nM. Moreover, the Fe-N-CQDs demonstrated wide range pH compatibility between 2 and 13 due to the coordination between pyridine nitrogen and Fe 3þ , which dramatically reduced the affection of the protonation and deprotonation process between H þ and Fe-N-CQDs. It is notable that the Fe-N-CQDs exhibited a rapid response in Cu 2þ detection, where stable quenching can be completed in 7 s. The mechanism of excellent selective detection of Cu 2þ was revealed by energy level simulation that the LUMO level of Fe-N-CQDs (À4.37 eV) was close to the redox potential of Cu 2þ , thus facilitating the electron transport from Fe-N-CQDs to Cu 2þ .
doi:10.1016/j.gee.2021.04.005 fatcat:hhntc5bfmvcltomtjo53a6hhc4