Open AccessGreen synthesis of N-doped carbon quantum dots for the detection of nitrite ion in water sample
Author(s) -
Jianwei Zhao,
Qi Song,
Fei Wu,
Xiao Guo,
Tong Xu
Publication year - 2019
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/344/1/012068
Subject(s) - x ray photoelectron spectroscopy , nitrite , analytical chemistry (journal) , photoluminescence , quantum yield , ion , fourier transform infrared spectroscopy , absorption (acoustics) , materials science , fluorescence , absorption spectroscopy , ultraviolet , raman spectroscopy , amorphous solid , chemistry , nuclear chemistry , nitrate , crystallography , nuclear magnetic resonance , optics , chromatography , optoelectronics , physics , organic chemistry , composite material
In this work, a green hydrothermal method was used to synthesize nitrogen-doped carbon quantum dots (N-CQDs) from Ecuadorian shrimp shell. X-ray diffraction (XRD) pattern showed that N-CQDs had an amorphous carbon peak. Both Fourier transform infrared (FT-IR) spectra and X-ray photoelectron (XPS) spectra indicated the presence of C, O and N in N-CQDs. The elemental analysis revealed that the weight percentage of C, H and N in N-CQDs are 45.7%, 6.9% and 13.2%, respectively. Transmission electron microscopy (TEM) image demonstrated N-CQDs had an average size of 3 nm and spherical shape. While quinine sulfate with 54% fluorescent quantum yield was used as a reference, the quantum output of N-CQDs was calculated to be 23.7%. Ultraviolet-visible absorption spectra of N-CQDs showed that the maximum absorption wavelength was 275 nm. Photoluminescence (PL) spectra of N-CQDs displayed highest PL intensity at excitation and emission wavelengths of 323 and 407 nm, respectively. The results showed that the synthesized samples were N-CQDs. N-CQDs can be used as a fluorescent probe for nitrite ions in water. However, nitrite ion was not detected in Hu County River water and Xi’an tap water. This may be due to the absence of nitrite ion in the selected water samples.