UV–visible photoresponse properties of self-seeded and polymer mediated ZnO flower-like and biconical nanostructures

Rajkumar, C; Srivastava, Rajneesh

doi:10.1016/j.rinp.2019.102647

Cited by 19 publications

(12 citation statements)

References 73 publications

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“…The new absorption peak at 651 cm −1 appears due to the attachment of the amide group and the stretching mode of ZnO [18,19]. The bands at 582 cm −1 may be ascribed to the Zn-O bond [20].…”

Section: Ftir Characterization Of Composite Materialsmentioning

confidence: 94%

Pollutants Sorbent Made of Cotton Fabric Modified with Chitosan-Glutaraldehyde and Zinc Oxide Particles

2021

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The paper reports on the preparation of composite materials by modifying cotton fabric with a layer of crosslinked glutaraldehyde chitosan containing zinc oxide particles. The ability of chitosan to form complexes with zinc ions has been used to control the size, structure, and distribution of the particles on the fiber surface. The three different obtained materials have been characterized by optical and scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and fluorescent analysis. It has been found that the interaction of the ZnO particles with the functional groups of chitosan affects its swelling ability in water and thus determines its sorption properties. The capacity of the materials to wipe water-soluble (textile reactive dye) and water-insoluble (crude oil and oil products) contaminants has been compared. The effect that the amount of zinc oxide has on the ability of the materials to remove contaminants has also been studied. The possibility for adsorption–desorption of the crude oil and reuse of the sorbent material has been investigated as well.

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Section: Ftir Characterization Of Composite Materialsmentioning

confidence: 94%

Pollutants Sorbent Made of Cotton Fabric Modified with Chitosan-Glutaraldehyde and Zinc Oxide Particles

2021

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“…Such a situation leads to different controversial hypotheses in the literature [17]. It was clearly shown that the bands of visible luminescence of ZnO are connected with the structural defects of their crystal lattice [17][18][19][20][21]. It was established that the short-wavelength visible emission of ZnO is correlated with the density of interstitial zinc (Zn i ) defects [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

“…It was clearly shown that the bands of visible luminescence of ZnO are connected with the structural defects of their crystal lattice [17][18][19][20][21]. It was established that the short-wavelength visible emission of ZnO is correlated with the density of interstitial zinc (Zn i ) defects [19][20][21]. Transitions from Zn i shallow defect levels to the top of the valence band are usually ascribed to the violet emission band at approximately 400-415 nm [17,[21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Effects of thermal treatment on the complex structure of luminescence emission of Li-doped ZnO screen-printed films

Chukova,

Borkovska,

Khomenkova

et al. 2023

Front. Phys.

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The ZnO–Li films were synthesized and investigated in an attempt to explore and develop RE-free phosphor materials capable of emitting intense visible light in a wide spectral range. The effects of both heterovalent doping with lithium and high-temperature annealing on the optical properties of ZnO films were studied. The films were deposited on the Al2O3 substrate using the screen-printing method and annealed at 800–1,000°C in air for 0.5–3 h. Both doping and annealing result in the transformation of the shape of reflectance spectra in the range of 300–400 nm and the shift of absorption edge to the long-wavelength region. At the same time, the bandgap value estimated taking into account the exciton peak position and its binding energy is independent of Li-doping. The feature at 300–400 nm and the shift of absorption edge are ascribed to the appearance of the absorption band that excited the yellow photoluminescence band. The photoluminescence spectra of undoped and Li-doped films show the emission bands in the ultraviolet and visible spectral ranges. The ultraviolet emission is due to ZnO exciton recombination. The visible emission band comprises several components peaked at 430, 482, 540, 575, and 640 nm. Their relative intensities depend on Li-doping, annealing temperature, and annealing duration. The 430- and 482-nm luminescence bands were observed in Li-doped films only. Their excitation spectra show the peak located at 330–340 nm, indicating that the energy significantly exceeds the ZnO bandgap energy. Consequently, the 430- and 482-nm luminescence bands are attributed to an additional crystal phase formed under annealing. Other components of visible emission bands are ascribed to the defect-related emission of ZnO. The possible nature of these bands is further discussed. Li-doping and annealing at intermediate temperatures result in blue emission and an enhancement of other visible bands, which makes ZnO–Li films a perspective material in photonic applications.

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“…Among the various kinds of NIR-reflective pigments, ZnO is well known as a multifunctional material due to its unique physical and chemical properties, such as wide bandgap (3.4 eV) [17], high chemical stability [18], and high photostability [19]. It is suitable for use as a coating powder due to its numerous advantages, such as non-toxicity to humans [20,21], biocompatibility [22], low cost [23], and high UV absorption [24,25] and NIR reflection [26] properties. The different conditions used for ZnO synthesis results in different ZnO morphologies.…”

Section: Introductionmentioning

confidence: 99%

Zinc Oxide Synthesis from Extreme Ratios of Zinc Acetate and Zinc Nitrate: Synergistic Morphology

et al. 2022

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The synthesis of ZnO comprising different ratios of zinc acetate (ZA) and zinc nitrate (ZN) from the respective zinc precursor solutions was successfully completed via a simple precipitation method. Zinc oxide powders with different mole ratios of ZA/ZN were produced—80/1, 40/1, and 20/1. The crystallinity, microstructure, and optical properties of all produced ZnO powders were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis-NIR spectrophotometry. The average agglomerated particle sizes of ZnO-80/1, ZnO-40/1, and ZnO-20/1 were measured at 655, 640, and 620 nm, respectively, using dynamic light scattering (DLS). The optical properties of ZnO were significantly affected by the extreme ratio differences in the zinc precursors. ZnO-80/1 was found to have a unique coral-sheet structure morphology, which resulted in its superior ability to reflect near-infrared (NIR) radiation compared to ZnO-40/1 and ZnO-20/1. The NIR-shielding performances of ZnO were assessed using a thermal insulation test, where coating with ZnO-80/1 could lower the inner temperature by 5.2 °C compared with the neat glass substrate. Due to the synergistic effects on morphology, ZnO-80/1 exhibited the property of enhanced NIR shielding in curtailing the internal building temperature, which allows for its utilization as an NIR-reflective pigment coating in the construction of building envelopes.

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UV–visible photoresponse properties of self-seeded and polymer mediated ZnO flower-like and biconical nanostructures

Cited by 19 publications

References 73 publications

Pollutants Sorbent Made of Cotton Fabric Modified with Chitosan-Glutaraldehyde and Zinc Oxide Particles

Pollutants Sorbent Made of Cotton Fabric Modified with Chitosan-Glutaraldehyde and Zinc Oxide Particles

Effects of thermal treatment on the complex structure of luminescence emission of Li-doped ZnO screen-printed films

Zinc Oxide Synthesis from Extreme Ratios of Zinc Acetate and Zinc Nitrate: Synergistic Morphology

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