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101.
《Ceramics International》2016,42(15):16852-16860
Green light emitting Zn2SiO4:Mn2+ phosphors have been synthetised by the solid-state reaction in ambient atmosphere at 1300 °C for 2 h, with ZnO, SiO2 and MnO2 as the reagents. The ZnO/SiO2 molar ratio varied from 2 to 0.5. The doping level was in a lower concentration range (0.01≤x≤0.05). The effect of both the Mn2+ concentration and ZnO/SiO2 molar ratio on luminescence intensity and decay was investigated in detail. The microstructure and phase composition of prepared phosphors were characterised by scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). XRD results indicate that the pure α-Zn2SiO4 phase with rhombohedral structure was obtained after heat treatment. The prepared phosphors exhibit a strong green emission centred at 525 nm from the 4T1→6A1 forbidden transition. The highest emission intensity was observed for phosphors with ZnO/SiO2 molar ratio equal to 1.0, and the Mn2+ concentration x=0.03 (ZSMn3). The emission intensity of the ZSMn3 phosphor is comparable with the commercial Zn2SiO4:Mn2+ phosphor. The decay curves can be characterised by double exponential function. After fitting a fast component τ1∼2 ms and a slow component τ2∼10 ms were obtained. The decay times decrease significantly with increasing Mn2+ concentration. The decay time and luminescence mechanism depend on the excitation light wavelength. Temperature dependent luminescence of the ZSMn3 phosphor in the temperature range of 25–200 °C was studied. 相似文献
102.
Anurag Gupta Bruce C. Kim Eugene Edwards Christina Brantley Paul Ruffin 《Materials Science and Engineering: B》2012,177(18):1583-1588
High-quality zinc oxide (ZnO) nanowires were synthesized using the atmospheric chemical vapor deposition technique and were appropriately characterized. Subsequently, the nanowire surface was covalently grafted with 1-pyrenebutyric acid (PBA) fluorophore, and surface-sensitive X-ray photoelectron spectroscopy and Fourier transform infrared-attenuated total reflectance spectroscopy were utilized to confirm the functionalization of 1-pyrenebutyric acid on the nanowire surface. Additionally, photoluminescence (PL) measurements were used to evaluate the optical behavior of pristine nanowires. Through fluorescence quenching of 1-pyrenebutyric acid by p-nitrophenol, a detection limit of 28 ppb was estimated. Based on these findings, ZnO nanowires functionalized with 1-pyrenebutyric acid are envisaged as extremely sensitive platforms for the ultra-trace detection of p-nitrophenol in biological systems. 相似文献
103.
Nanocomposite buffer layer based on metal oxide and polymer is merging as a novel buffer layer for organic solar cells, which combines the high charge carrier mobility of metal oxide and good film formation properties of polymer. In this work, a nanocomposite of zinc oxide and a commercialized available polyethylenimine (PEI) was developed and used as the cathode buffer layer (CBL) for the inverted organic solar cells and p-i-n heterojunction perovskite solar cells. The cooperation of PEI in nano ZnO offers a good film forming ability of the composite material, which is an advantage in device fabrication. In addition, power conversion efficiency (PCE) of the ZnO:PEI CBL based device was also improved when compared to that of ZnO-only and PEI-only devices. The highest PCE of P3HT:PC61BM and PTB7-Th:PC61BM devices reached to 3.57% and 8.16%, respectively. More importantly, there is no obvious device performance loss with the increase of the layer thickness of ZnO:PEI CBL to 60 nm in organic solar cells, which is in contrast to the PEI based devices, whose device performance decreases dramatically when the PEI layer thickness is higher than 6 nm. Such a nano composite material is also applicable in inverted heterojunction perovskite solar cells. A PCE of 11.76% was achieved for the perovskite solar cell with a thick ZnO:PEI CBL (150 nm) CBL, which is around 1.71% higher than that of the reference cell without CBL, or with ZnO CBL. In addition, stability of the organic and perovskite solar cells having ZnO:PEI CBL was also found to be improved in comparison with that of PEI based device. 相似文献
104.
Hyeong Pil Kim Abd Rashid bin Mohd Yusoff Hyo Min Kim Hee Jae Lee Gi Jun Seo Jin Jang 《Nanoscale research letters》2014,9(1):150
We demonstrate that there is a new solution-processed electron transport layer, lithium-doped zinc oxide (LZO), with high-performance inverted organic photovoltaic device. The device exhibits a fill factor of 68.58%, an open circuit voltage of 0.86 V, a short-circuit current density of −9.35 cm/mA2 along with 5.49% power conversion efficiency. In addition, we studied the performance of blend ratio dependence on inverted organic photovoltaics. Our device also demonstrates a long stability shelf life over 4 weeks in air. 相似文献
105.
Eugene Chong Sarah Kim Jun-Hyuk Choi Dae-Geun Choi Joo-Yun Jung Jun-Ho Jeong Eung-sug Lee Jaewhan Lee Inkyu Park Jihye Lee 《Nanoscale research letters》2014,9(1):428
Fabrication of ZnO nanostructure via direct patterning based on sol-gel process has advantages of low-cost, vacuum-free, and rapid process and producibility on flexible or non-uniform substrates. Recently, it has been applied in light-emitting devices and advanced nanopatterning. However, application as an electrically conducting layer processed at low temperature has been limited by its high resistivity due to interior structure. In this paper, we report interior-architecturing of sol-gel-based ZnO nanostructure for the enhanced electrical conductivity. Stepwise fabrication process combining the nanoimprint lithography (NIL) process with an additional growth process was newly applied. Changes in morphology, interior structure, and electrical characteristics of the fabricated ZnO nanolines were analyzed. It was shown that filling structural voids in ZnO nanolines with nanocrystalline ZnO contributed to reducing electrical resistivity. Both rigid and flexible substrates were adopted for the device implementation, and the robustness of ZnO nanostructure on flexible substrate was verified. Interior-architecturing of ZnO nanostructure lends itself well to the tunability of morphological, electrical, and optical characteristics of nanopatterned inorganic materials with the large-area, low-cost, and low-temperature producibility. 相似文献
106.
Enhanced photocatalytic hydrogen production of noble-metal free Ni-doped Zn(O,S) in ethanol solution
Noto Susanto Gultom Hairus Abdullah Dong-Hau Kuo 《International Journal of Hydrogen Energy》2017,42(41):25891-25902
High efficient hydrogen evolved Ni-doped Zn(O,S) photocatalyst with different Ni amounts had been successfully synthesized with a simple method at low temperature. Our Ni-doped Zn(O,S) catalyst reached the highest hydrogen generation rate of 14,800 μmol g?1 h?1 or 0.92 mmol g?1 h?1 W?1 corresponding to apparent quantum yield 31.5%, which was 2.3 times higher compared to the TiO2/Pt used as a control in this work. It was found that a small amount of Ni doped into Zn(O,S) nanoparticles could increase the optical absorbance, lower the charge transfer resistance, accordingly decrease the electron-hole recombination rate, and significantly enhance the photocatalytic hydrogen evolution reaction (HER). The as-prepared catalyst has the characteristics of low cost, low power consumption for activating the catalytic HER, abundant and environmental friendly constituents, and low surface oxygen bonding for forming oxygen vacancies. The photocatalytic performance of Ni-doped Zn(O,S) was demonstrated with a proposed kinetic mechanism in this paper. 相似文献
107.
Bekelcha T. Gadisa Anteneh F. Baye Richard Appiah-Ntiamoah Hern Kim 《International Journal of Hydrogen Energy》2021,46(2):2075-2085
In this study, an electrocatalyticaly inactive ZnO@Ni foam photoelectrode was modified with heteroatom doped graphitic carbon to achieve enhanced photoelectrochemical (PEC) water splitting performance. The O, S and N doped graphitic carbon was simultaneously deposited with ZnO on Ni foam substrate under hydrothermal deposition. One dimensional ZnO nanorods with flower-like graphitic carbon on their surface were obtained on the Ni foam substrate, which was directly used as photoelectrode to derive photoelectrochemical water splitting under solar light irradiation. The pristine ZnO@NF exhibit unattractive PEC performance evidenced by the high overpotential required for the oxygen evolution reaction (OER) couple of water splitting reaction (398 mV vs. RHE). The carbon modified ZnO–C@NF photoelectrode lowers the overpotential required to 317 mV. This enhancement was attributed to the carbon modification which serves as both active site and photoelectron reservoir; facilitating the sluggish kinetics of OER couple reaction and promoting separation of photogenerated charge carriers. 相似文献
108.
《Food Control》2014
Zinc oxide nanoparticles were prepared using hydrothermal synthesis approach. Formation of zinc oxide nanoparticles were confirmed by using UV–Vis spectrophotometer, Fourier transform infrared spectrometer and X-ray diffractometer. The particles size (≤100 nm) and structure of nanoparticles were studied under scanning and transmission electron microscope. The nanoparticles were used against two prominent foodborne pathogens, Salmonella typhimurium and Staphylococcus aureus and were found highly effective against both of them. The antibacterial activity of the nanoparticles was determined in solid and liquid media using nutrient agar and broth. Zinc oxide nanoparticles loaded active film of calcium alginate was prepared for active packaging against the same foodborne pathogens (S. typhimurium and S. aureus). Presence and distribution of nanoparticles in active film were confirmed with Fourier transform infrared spectrometer, X-ray diffractometer and scanning electron microscopy. Zinc oxide nanoparticles loaded active films showed antibacterial activity against the target bacteria in Petri dish. The film was also used as an active packaging (a challenge study) in ready-to-eat poultry meat against the same pathogens, and reduced the number of inoculated target bacteria from log seven to zero within 10 days of its incubation at 8 ± 1 °C. 相似文献
109.
《Ceramics International》2017,43(9):6709-6720
Zinc Oxide (ZnO) nanoparticles were synthesized by wire explosion process through deposition of different levels of energy to the exploding conductor in oxygen ambience at different pressures. The produced nanoparticles were analyzed by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDAX) and by Brunauer-Emmett-Teller (BET) studies. Energy dependent formation reaction mechanisms were formulated based on Born-Haber cycle. The size dependent gas phase reaction energetics was analyzed by using Hess's diagram. Butler's multicomponent molten oxide model was adopted to predict the surface tension of ZnO. Thermodynamic modelling studies revealed that the amount of energy deposited has an impact on saturation ratio, activation free energy, and nucleation rate of nanoparticles. It is observed based on experimental and modelling studies that the amount of energy deposited to the current carrying conductor, ambient pressure of oxygen and the saturation ratio influence the size of nanoparticle formed. 相似文献
110.
Phase equilibria of the binary PbO-ZnO and ternary PbO-ZnO-SiO2 systems have been experimentally investigated at 1033–1898?K (760–1625?°C) for oxide liquid in equilibrium with air and solid oxide phases: tridymite or cristobalite (SiO2), willemite (Zn2SiO4), zincite (ZnO), larsenite (PbZnSiO4) and lead-zinc melilite (Pb2ZnSi2O7) covering the ranges of concentrations not studied before. High-temperature equilibration on primary phase or inert metal (platinum) substrates, followed by quenching and direct measurement of the Pb, Zn and Si concentrations in the phases with the electron probe X-ray microanalysis (EPMA) has been used. Liquidus phase equilibrium data is essential for the development of the thermodynamic model. 相似文献