Polysulfide ligand exchange on zinc sulfide nanocrystal surfaces for improved film formation

Herron, Steven M.; Lawal, Qudus Omotayo; Bent, Stacey F.

doi:10.1016/j.apsusc.2015.10.059

Cited by 23 publications

(3 citation statements)

References 43 publications

(39 reference statements)

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“…QD‐OA, QDs with TP ligands (QD‐TP), QDs with 4‐MTP ligands (QD‐MTP), and QDs with 4‐DMATP ligands (QD‐DMATP) were analyzed via Fourier transform infrared (FTIR) spectroscopy as shown in Figure . All the QDs have strong intensities at 1422–1456 and 1544 cm −1 , which were assigned to stretching vibration of carboxylate on the QD surfaces, as previously reported . The QD‐TP exhibited two peaks at 692 and 737 cm −1 , which were assigned to the C–H bending vibration of TP without any functional group.…”

Section: Key Characteristics Of the All‐solution‐processed Inverted‐ssupporting

confidence: 75%

Efficiency Enhancement of All‐Solution‐Processed Inverted‐Structure Green Quantum Dot Light‐Emitting Diodes Via Partial Ligand Exchange with Thiophenol Derivatives Having Negative Dipole Moment

Moon

Chae

2019

Advanced Optical Materials

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Thiophenol derivatives having a negative dipole moment such as thiophenol (TP), 4‐methylthiophenol (4‐MTP), and 4‐(dimethylamino)thiophenol (4‐DMATP) are incorporated into quantum dots (QDs) and the efficiency of all‐solution‐processed inverted‐structure quantum dot light‐emitting diodes (QLEDs) is enhanced. The negative dipole moments of TP, 4‐MTP, and 4‐DMATP are attributed to the enhancement of the efficiency of the QLEDs. The valence band maximum (VBM) of the QDs is upshifted, and the energy gap between the VBM and the highest molecular orbital level of the hole transport layer is reduced to −0.16 from 0.46 eV by the negative dipole moment of thiophenol derivatives. The electron and hole transport of the QDs are accelerated, and charge balance is achieved at 5 V with a reduction of 1.25 V by the thiophenol derivatives. The QLEDs with 4‐DMATP exhibit a maximum luminance of 106 400 cd m−2, a maximum current efficiency of 98.2 cd A−1, and an external quantum efficiency (EQE) of 24.8%. The EQE of 24.8% is the highest value reported thus far for all‐solution‐processed inverted‐structure single‐device QLEDs, to the best of knowledge. Improvement by factors of 2.99, 1.57, and 1.54 are achieved in the maximum luminescence, maximum current efficiency, and EQE respectively, compared with a QLED with OA ligands.

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Section: Key Characteristics Of the All‐solution‐processed Inverted‐ssupporting

confidence: 75%

Efficiency Enhancement of All‐Solution‐Processed Inverted‐Structure Green Quantum Dot Light‐Emitting Diodes Via Partial Ligand Exchange with Thiophenol Derivatives Having Negative Dipole Moment

Moon

Chae

2019

Advanced Optical Materials

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“…It means that there are not many carbon deposits on the surface, which is consistent with EDS results. For Sulfur XPS spectra in Figure 6b, peaks of 162.4 eV and 163.6 eV are attributed to the peaks of S2p spectra of ZnS and NiS, respectively, which proves the existence of intermediate species NiSx [28,29]. According to Babich and Moulijin's mechanism, the transient state NiSx will react with H2 immediately, therefore, the peaks of NiSx cannot be detected in XRD results.…”

Section: X-ray Photoelectron Spectroscopy (Xps) Characterizationmentioning

confidence: 92%

The Role of NiO in Reactive Adsorption Desulfurization Over NiO/ZnO-Al2O3-SiO2 Adsorbent

Wang

et al. 2019

Catalysts

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The reactive adsorption desulfurization (RADS) of a model gasoline n-hexane containing thiophene was carried out with a NiO/ZnO-Al2O3-SiO2 adsorbent in N2 and H2, respectively. A declining RADS trend has been observed in N2, without the presence of H2, indicating that NiO is sulfurized and exhibits activity for RADS. TPR and XPS results presented NiO in the adsorbent is hard to be reduced because of the powerful interaction between NiO and the support. The sulfurization of NiO into NiSx is a primary condition for the RADS process, the same as the presulfurization of hydrotreating catalyst, while metallic Ni is an intermediate reduction product of NiSx. Results of a low RADS temperature at 300 °C, much lower than the reduction temperature of NiO, suggest that NiO plays an important role. Based on assumption of NiO as the main active component, the RADS could reduce the reaction temperature and energy consumption significantly. The participation of hydrogen and n-hexane in pretreatment conducted at 420 °C contributes to the activation of adsorbent. Also, these methods of pretreatment improved the desulfurization performance under the reaction temperature of 300 °C.

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“…Fig. 5b shows the curve fitting results of S2p in the sample treated by Pb(NO3)2 and Na2S successively, in which the binding energy of the first set of split peak was 162.73 eV, corresponding to the polysulfide (Sn 2-) (Feng and Wen, 2017;Herron et al, 2015;Smart et al, 1999). In the second set of the split peak, the binding energy of S2p3/2 was 161.24eV, which should be the monosulfide (S 2-) (Li et al, 2018).…”

Section: Formation Of Lead and Sulfur Speciesmentioning

confidence: 98%

Lead species formation on pure hemimorphite surface and its performance for subsequent sulfidization

Liang,

Zhang,

Xian

et al. 2024

Physicochem. Probl. Miner. Process.

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Hemimorphite is important-supplementary resource for the commercial zinc production, but it easy loses into tailings due to extreme difficulty for its surface sulfidization. Adding active metal ions after sulfidization have been widely proposed for enhancing hemimorphite floatability, but its desired efficiency in flotation practice has not yet been completely achieved caused by the instability of sulfide layer. Whereas pre-adsorption of active metal ions to modify the hemimorphite surface has strong potential to make up for this shortcoming. Herein, the feasibility and appropriate environment of free Pb2+ for modifying the pure hemimorphite surface was evaluated. Subsequently, the performance of Pb2+ adsorption for enhancing sulfidization stability and floatability of hemimorphite were investigated. The X-ray photoelectron spectroscopy results indicated that the Pb2+ adsorption on hemimorphite surface was achieved through the Pb ions displacement for Zn ions, and it was bond to oxygen-containing groups on hemimorphite surface. Such adsorption was strengthened with the increasing of solution pH, owing to the abundant Pb hydroxyl species precipitated on mineral under alkaline conditions, in term of the results of visual MINTEQ modeling and time-of-flight secondary-ion mass spectrometry. In addition, the X-ray photoelectron spectroscopy results showed dominant Pb hydroxyl species further reacted with sulfur during subsequent sulfidization to generate much more S species than that of without Pb2+ pre-modification. Meanwhile, such sulfide layer composed by Pb2+ on the mineral surface presented much higher stability than Zn-S species, which was verified via adsorption and desorption tests. As a result, the sulfidization and flotation recovery of hemimorphite increased after Pb2+ pre-adsorption.

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Polysulfide ligand exchange on zinc sulfide nanocrystal surfaces for improved film formation

Cited by 23 publications

References 43 publications

Efficiency Enhancement of All‐Solution‐Processed Inverted‐Structure Green Quantum Dot Light‐Emitting Diodes Via Partial Ligand Exchange with Thiophenol Derivatives Having Negative Dipole Moment

Efficiency Enhancement of All‐Solution‐Processed Inverted‐Structure Green Quantum Dot Light‐Emitting Diodes Via Partial Ligand Exchange with Thiophenol Derivatives Having Negative Dipole Moment

The Role of NiO in Reactive Adsorption Desulfurization Over NiO/ZnO-Al2O3-SiO2 Adsorbent

Lead species formation on pure hemimorphite surface and its performance for subsequent sulfidization

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