Fig 2 - uploaded by Bichitra Ganguly
Content may be subject to copyright.
EDAX data: a purity check of the ZnO sample as synthesized through sol-gel chemical route, inset shows the ZnO nano particles with fringed structure of the crystalline sample from TEM picture.
Source publication
Nano-crystalline ZnO has been studied with perturbed angular correlation using 111mCd, implanted at ISOLDE/CERN and X-ray diffraction using Rietveld analysis. The data show a gradual increase in the crystal size and stress for a sample annealed at 600 °C, and reaching nearly properties of standard ZnO with tempering at 1000 °C. The perturbed angula...
Contexts in source publication
Context 1
... the elemental purity check of the ZnO samples, Energy Dispersive X-ray analysis (EDAX/SEM) and scanning microscopic analysis of the grain surface was performed using Quanta FEG-200, FEi Company USA. As prepared ZnO sample sintered at 200 °C, has been dispersed in pure water then TEM examination was performed after placing a drop of the same on the carbon coated grid and dried under vacuum. Measurements were done with (Tecnai S-twin, FEI) using an accelerating voltage of 200 kV, having a resolution of %1 Å. The results of such analysis are shown in Fig. ...
Context 2
... samples prepared by aqueous sol-gel technique were dried under vacuum at 100 °C over night, and the characteristic FT-IR frequencies were checked as shown in Fig. 1 and Table 1 for any residual organic groups. These data represent the as-prepared ZnO material. Some residual acetate groups (C@O) could be detected. Presence of moisture is also detected; this could be dependent on the ambient condition. It was considered as the pre- cursor material for ZnO, which was sintered later to proceed for evolution of pure and dried material of ZnO. The elemental purity of ZnO was checked with the help of EDAX spectrum as shown in Fig. 2. From TEM results of pure ZnO samples (dried at 200 °C was used), the fringe structure of ZnO sample showed crystallinity of the material (as shown by the arrow). The mean size as esti- mated from the TEM image has been about %10 nm (average size as measured with the size bar shown in the figure) and clearly indi- cates that the initially annealed ZnO nano-particles are crystalline with a wurtzite structure [41]. No other impurities were ...
Citations
... The broad dip at around 3418 cm -1 is because of the stretching vibration of O-H in the hydroxyl groups [33]. The dips at 1646, 1560 and 1412 cm -1 correspond to C=C, C=O and C-O, respectively, in the FT-IR spectra for undoped ZnONPs that are due to vibrations of bonds connecting a carbon atom to other ions [34][35][36]. The carbon may come from the CO2 absorbed by the NPs while they were being stored. ...
The morphological, optoelectronic, and dye degrading properties of Ag doped ZnONPs are reported herein which were fabricated using different concentrations of Ag and a hydrothermal method. The size of ZnONPs ranged from 33 to 45 nm. UV-Visible spectroscopy revealed a red- shift of the absorbance spectra confirming band gap reduction after Ag doping. The four luminescence peaks for the ZnONPs included a blue luminescence peak between 440 and 470 nm, a green luminescence peak between 470 and 570, a yellow luminescence peak between 570 and 585 nm, and a red luminescence peak between 585 and 780 nm. Superior photocatalytic dye degradation was noted where the 5% Ag-doped ZnONPs exhibited 99.12 % photocatalytic phenol degradation after 24 h with a rate constant equivalent to 0.2099 k (min-1) while the rate constants of 2.5922 and 2.3392 k (min⁻¹) for the degradation of Rhodamine B and methylene blue dyes, respectively. Hence, the present Ag-doped ZnONPs should be further studied for diverse photocatalytic applications.
This article has attempted to produce and characterize PVA/ZnO nanocomposite membranes with varying percentages of zinc oxide nanoparticles for appropriate applications. Polymer-nanocomposite membranes were created using the solution-cast approach, utilizing a matrix of poly(vinyl alcohol) (PVA) and zinc oxide (ZnO) nanoparticles (i.e., (PVA)–x wt% ZnO; x = 0, 1, 3, 5, and 7 wt%). FTIR spectroscopy, scan electron microscope (SEM), surface roughness (SR), and optical microscopy techniques (UV–visible, and photoluminescence) were used to study the development and alterations in the structuralism and optically feature of the nanocomposite membranes. Scanning electron microscopy and a surface roughness tester were used to clarify the surface morphology of PVA/ZnO hybrid membranes. FTIR spectra clearly show the interactions that exist between ZnO and the host PVA polymer matrix. SEM micrographs demonstrated that the PVA polymer matrix contains a dispersed collection of homogeneously distributed nanofillers. It is interesting that nanofillers own an impact on the surface roughness of PVA membrane. PVA-ZnO hybrid membranes exhibit a red shift in their optical absorption spectra as the ZnO ratio increases. The direct band gap decreases from 5.60 to 4.30 eV and the indirect band gap decreases from 4.80 to 3.40 eV as the ZnO content increases. The amended optical parameters, like absorbance and band gap, refractive index, complex dielectric permittivity accentuate the adaptability of these nanostructures in several optoelectronic applications. According to photoluminescence investigations, the strength of the resultant emission changes as ZnO nanoparticle concentration changes.
An organic-inorganic nanohybrid system (AMC-CdS QD) comprised of a fluorescent carbazole analog, AMC (3-amino-N-methyl carbazole), and CdS QDs has been synthesized, which shows promise as a sustainable energy harvesting material. FT-IR and ¹H NMR spectroscopy have ascertained the covalent grafting of the carbazole moieties onto the mercaptopropionic acid (MPA)-capped surface of the CdS QDs. Detailed photophysical characterization of this nanohybrid system have confirmed the efficient Fӧrster resonance energy transfer (FRET) observed from its organic to inorganic counterpart. This phenomenon was also demondtrated using SCC-DFTB-based quantum chemical calculations. As explored in the present work, the photoelectron transfer efficiency of AMC-CdS QDs signifies their plausible future applications as light-harvesting materials.
