A novel luminescence probe based on layered double hydroxides loaded with quantum dots for simultaneous detection of heavy metal ions in water

Liu, Jieyuan; Lv, Guocheng; Gu, Wenlong; Li, Zhaohui; Tang, Aiwei; Mei, Lefu

doi:10.1039/c7tc00935f

Cited by 59 publications

(32 citation statements)

References 59 publications

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“…The XRD pattern of Mg−Al LDH provides information about the Bragg reflection phase, nature and a high degree of coordination, and the narrow diffraction peaks illustrate the high crystallinity and purity. The XRD pattern of the hexagonal phased Mg−Al LDH sample is in good agreement with the JCPDS card no: 35–0965 . The diffraction peaks indexed to (003), (006), (012), (015), (018), and (110) are the plane reflections of a typical hydrotalcite‐like phase screening sharp and symmetric basal (00 l) reflection.…”

Section: Resultssupporting

confidence: 78%

Photodegradation Activity of Nitrogen‐rich Graphitic Carbon Nitride Intercalated ZnO\Mg‐Al Layered Double Hydroxide Ternary Nanocomposites on Methylene Blue Dye

et al. 2019

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Herein, we report the preparation and visible light-triggered photocatalytic investigation of nitrogen-rich graphitic carbon nitride (g-C 3 N 4 ) nanosheets intercalated ZnO\MgÀ Al LDH (2D \2D) ternary nanocomposite. The ZnO nanoparticles, unique structured LDH, and g-C 3 N 4 are intercalated well by the hydrothermal treatment, showing a significant enhancement in the visible light absorption and corresponding photocatalytic activity. Formation of this new ternary nanocomposite was examined by using XRD, FE-SEM, TEM, FTIR, EDX, Elemental mapping, XPS and UV-Vis analysis. The ternary nanocomposite photocatalyst show remarkable performance towards the photodegradation of Methylene Blue (MB) dye. The ternary nanocomposite exhibited considerable improvement in the photocatalytic activity and is attributed to the N-rich g-C 3 N 4 and even distribution of ZnO\MgÀ Al LDH over the g-C 3 N 4 surface. This work offers a facile approach to prepare a novel visible light-response photocatalyst for photocatalytic dye degradation of organic pollutants.

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Section: Resultssupporting

confidence: 78%

Photodegradation Activity of Nitrogen‐rich Graphitic Carbon Nitride Intercalated ZnO\Mg‐Al Layered Double Hydroxide Ternary Nanocomposites on Methylene Blue Dye

et al. 2019

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“…Furthermore, the detection of metal ions using PL of QDs is not limited to Hg 2+ , Pb 2+ and Cd 2+ as it depends on the reduction potential. Interestingly, it can be noticed that the metal ions detected by PL quenching method in the earlier reports possess high reduction potentials, which supports our proposed mechanism.…”

Section: Resultsmentioning

confidence: 49%

“…It is not possible to bring selectivity using this method as claimed in several earlier reports, because many metal ions are found to associate with the QD due to the extent of stabilization, different orbital overlap, and relative position of the accepting energy level through the electron injection mechanism. In fact, in earlier reports, we find that when Pb 2+ quenches emission, Hg 2+ and Cu 2+ also quenches the emission . In a few cases even the high reduction potential metal ions were not even reported .…”

Section: Resultsmentioning

confidence: 67%

“…In literature, we find reports of various QDs with different passivating ligands to detect heavy metal ions using their PL quenching . One such common ligand is glutathione (GSH).…”

Section: Resultsmentioning

confidence: 99%

“…Both these reports claimed that the specific interaction between the passivating ligands and the metal ions causes the aggregation of the QDs, which decreases their PL. In another report, GSH passivated Mn‐doped ZnS on layered double hydroxide detects Pb 2+ and Hg 2+ . The authors proposed a different mechanism – the cation exchange between the QD and the metal ion, decreases the PL.…”

Section: Resultsmentioning

confidence: 99%

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Origin of Luminescence‐Based Detection of Metal Ions by Mn–Doped ZnS Quantum Dots

et al. 2019

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The health hazards associated with heavy metal ions in water demand the development of efficient and portable sensors, for rapid onsite detection of these ions. Several research groups have developed colorimetric/visual sensors based on plasmonic nanomaterials and quantum dots (QDs). Attempts for specific detection of metal ions have been partially achieved through the interaction between the metal ion and the passivating ligands around the QD. However, the underlying mechanism is not clearly understood. Here, we have used water-soluble Mndoped ZnS QD to effectively detect Hg 2 + , Pb 2 + , and Cd 2 + through the quenching of QD emission and understand the mechanism of sensing. Stern-Volmer plots indicate that the quenching is static in nature for Pb 2 + , and Cd 2 + , while for Hg 2 + , it is a combination of static and dynamic quenching. Overall, the metal ions bind to the QD through the passivating ligand. After excitation, the electron from the conduction band of the QD can get injected to the metal ion -which decreases the photoluminescence of the QD. The electron injection depends on the reduction potential of the metal ion, the orbital overlap and the overall stabilization energy of the metal ions bound to the QD. Hence, this method of sensing is not selective to a specific metal ion. A solid state sensor of QD-rGO composite detects Pb 2 + down to 0.4 ppb. The findings will be important for future improvement of colorimetric/visual sensors based on QD emission.Heavy metal ions such as lead, mercury and cadmium pose severe potential threats to living beings as they can easily be accumulated in the body and cannot be detoxified by any chemical or biological processes. [1][2][3] Detections of these toxic metal ions are important and have received considerable interest. [4][5][6][7][8][9][10][11][12] Instrumental techniques such as inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS) are considered ideal methods to detect heavy metal ions at very low concentrations (∼ subppb). However, these methods suffer from disadvantages such as requirement of sophisticated instruments, time consump-tion, and high cost. Detecting heavy metal ions using rapid and easy methods with high sensitivity is a focal point of research.In the last two decades, there has been a significant development of several optical, [4][5][6][7] electrochemical, [8][9][10] and gel based sensors, [11,12] for sensing of heavy metal ions at trace levels (∼ 10 ppb). Sensors based on plasmonic nanomaterials show a change in color (shift in absorption wavelength) upon addition of the toxic heavy metal ions, depending upon the affinity of the heavy metal ion towards the surface capping agent on the nanoparticles. [13][14][15][16] These methods are restricted to solution state sensing and do not exhibit quick response. Therefore, there is an urge to develop visual sensors, which can effectively detect heavy metal ions rapidly (within seconds) under ambient conditions. [17] Due to their tunable and high photolumin...

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A First Wide‐Open LDH Structure Hosting InP/ZnS QDs: A New Route Toward Efficient and Photostable Red‐Emitting Phosphor

et al. 2021

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The architecture of Zn‐Al layered double hydroxides (LDHs), organo‐modified with bola‐amphiphiles molecules, is matching its interlayer space to the size of narrow‐band red‐emitting InP/ZnS core–shell quantum dots (QDs) to form original high‐performance functional organic–inorganic QD‐bola‐LDH hybrids. The success of size‐matching interlayer space (SMIS) approach is confirmed by X‐ray diffraction, small angle X‐ray scattering (SAXS), TEM, STEM‐HAADF, and photoluminescence investigations. The QD‐Bola‐LDH hybrid exhibits a photoluminescence quantum yield three times higher than that of pristine InP/ZnS QDs and provides an easy dispersion into silicone‐based resins, what makes the SMIS approach a change of paradigm compared to intercalation chemistry using common host structures. Moreover, this novel hybrid presents low QD–QD energy transfer comparable to that obtained for QDs in suspension. Composite silicone films incorporating InP/ZnS (0.27 wt%) QD‐bola‐LDH hybrids further show remarkable improved photostability relative to pristine QDs. An LED overlay consisting of a blue LED chip and silicone films loaded with QD‐bola‐LDH hybrids and YAG:Ce phosphors exhibits a color rendering index close to 94.

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A novel luminescence probe based on layered double hydroxides loaded with quantum dots for simultaneous detection of heavy metal ions in water

Abstract: A remarkable improvement in luminescence intensity was achieved by immobilizing quantum dots on the surface of layered double hydroxides, for the detection of heavy metals in real water samples.

Cited by 59 publications

References 59 publications

Photodegradation Activity of Nitrogen‐rich Graphitic Carbon Nitride Intercalated ZnO\Mg‐Al Layered Double Hydroxide Ternary Nanocomposites on Methylene Blue Dye

Photodegradation Activity of Nitrogen‐rich Graphitic Carbon Nitride Intercalated ZnO\Mg‐Al Layered Double Hydroxide Ternary Nanocomposites on Methylene Blue Dye

Origin of Luminescence‐Based Detection of Metal Ions by Mn–Doped ZnS Quantum Dots

A First Wide‐Open LDH Structure Hosting InP/ZnS QDs: A New Route Toward Efficient and Photostable Red‐Emitting Phosphor

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