Journal of Nano Structures
Volume:10 Issue: 4, Autumn 2020

Preparation of gold nanoparticles (AuNPs) was done by the addition of tetrachloroaurate (HAuCl4) to dodonaea viscose (L.) leaves watery extract. The procedure was performed in microwave-assisted extraction (MAE). Dodonaea viscose (L.) watery extract functions as a reducing and capping agent to synthesis AuNPs. The gold nanoparticles was identified by the changes in colour from yellow to red –purple, UV-vis spectroscopy, and surface plasmon band at (600 nm). (EDX -FESEM) and TEM instruments were used to investigate the element analysis, distribution of nanoparticles and to calculate their sizes and shapes. Energy dispersive X-ray spectra (EDX) was applied for characterization of gold nanoparticles, the detected percentage of gold nanoparticles was (0.52 wt/wt %). The result from TEM shows the nanoparticles with diameter (6-80 nm) and vary shapes. Furthermore, characterization of nanoparticles was performed before and after the formation of gold nanoparticles using FT-IR. The band appeared at 669 cm-1 indicated the gold nanoparticle formation. The synthesized gold nanoparticles have been used for degradation of 6.6 % methylene blue organic dye pollutant in aqueous solution, and also for degradation of aliphatic hydrocarbons in crude oil. The results of degradation were monitored by GC-MS. The breakage of some organic materials and the appearance of new organic materials with less molecular weight and less abundance were achieved. Through the use of gold nanoparticles, it has been observed that a large number of aliphatic compounds have disappeared, especially those with molecular weights 200-288, the loss in the molecular weight is about 40%.

The present work displays the use of natural dyes extracted from native plants as sensitizer for fabrication of dye-sensitized solar cells (DSSCs). The native plants named as comellia sinensis, punica granatum L. var sativa k.maly, morus nigra, rubia tinctorum and brassica oleracea were collected from Kashan area, Iran. The extracted dyes were characterized with the aid of UV–Vis and Fourier transform infrared (FT-IR) spectroscopies. The FT-IR results revealed the presence of hydroxyl groups in the chemical structures of the natural dyes, improving the interaction of between photosensitizer and TiO2 surface in solar cell devices. In addition, photoelectrochemical performance of the DSSCs based on the natural dyes illustrated short-circuit photocurrent (Jsc) and open-circuit voltages (Voc) ranging from 0.5 to 2.36 mA/cm2 and 0.38 to 0.62 V, respectively. Since cyanidin- glucoside compounds were the main pigment of brassica oleracea, interaction between plenty of hydroxyl groups of these compounds and TiO2 surface was very efficient, this sensitizer owned the best photovoltaic performance among all the natural dyes.

In the modern lifestyle, environmental stresses have substantially influenced human life. Evidence indicates that noise exposure can lead to anxiety-like behaviors. In recent years, advances in nanotechnology have favorably impacted industrial productions. In the present study, we aimed to evaluate the effect of Zinc/Iron oxide nanocomposites on anxiety-like behavior. Using gelatin, Zinc/Iron oxide nanocomposites were synthesized by the sol-gel modified method. Four groups of rats were exposed to sound stress for 12 days. Three groups received 1.25, 2.5, and 5 mg/kg of Zinc/Iron oxide nanocomposites before the noise stress. Also, three control animals received the same doses of the nanocomposites. One group of the stressed (ST) and control (CO) rats received saline. The animals were introduced to the elevated plus maze (EPM) for the assessment of anxiety. Entry to closed arms, duration of stay in open arms were considered for data analysis. We observed a significant difference between the behavior of the CO and ST animals so that the latter group showed more anxiety compared to the former one. Concerning the effect of Zinc/Iron oxide nanocomposites, the data analysis confirmed the positive effect of the dose of 2.5 mg/kg where the stressed animals treated with this dose of the nanocomposites considerably improved their normal performance in the EPM.

ZnS nanowires films on Si (100) substrate have been obtained, using PbS as dopant, via thermal evaporation technique. High resolution transmission electron microscopy (HRTEM) images have confirmed the formation of ZnS nanowires. Energy dispersive X-ray analysis (EDX) has been employed to investigate the element’s contents (mapping and area analysis) and it has confirmed that the ZnS films were stoichiometry. Thickness and morphology of the films were explored from cross section of the films and surface, respectively, using scanning electron microscopy (SEM) and atomic force microscopy (AFM) images. These images confirmed the creation of ZnS nanostructures morphology. The diameter of the obtained nanowires is about 50 nm and their length is several micrometer. Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), and Photoluminance (PL) have confirmed the hexagonal phase with nanowires structure. UV-Vis characterization has been used to obtain the transparency and the band gap of ZnS films deposited on glass substrate. Also, these verified characterizations allowed to potential optical application in optoelectronic field

Graphene nanoplatelets (GNP) / Acrylonitrile butadiene rubber (NBR) nanocomposites were prepared by solutions mixing method and vulcanized effectively. GNP suspension dispersed homogenously in a well-suited solution of NBR up to 2.4 phr and characterized by X-ray Diffraction (XRD). The influence of GNP on the cross-linking of GNP/NBR nanocomposites structure has been characterized and studied by the cure characteristics and swelling tests. The results showed that the cross-linking density was enhanced to 42.3% compared to that of unfilled NBR by reducing the swelling ratio to 19.7% at 1.2 phr of the GNP. Thus, the mechanical properties were investigated and revealed that the modulus at 100% elongation (M100) improved to about 155% and the hardness to about 13%. Those results were verified via the morphology analyzing using Scanning Electron Microscopy (SEM) and the enhancement of the storage modulus as a function of temperature in the rubber nanocomposite to about 100% utilizing Dynamic Mechanical Analysis (DMA) at the same content 1.2 phr of GNP.

In this paper the electrical characteristics of a nano scale silicon gate-all-around field effect transistor (GAA-FET) with different dielectrics in the gate electrode are predicted. For this, we first calibrate physics based TCAD simulator against experimental results reported by IBM. Then the device electrical figures of merit comprised of ION/IOFF, transconductance (gm) and subthreshold slope (SS) are extracted. The obtained results show that utilizing various high-k gate dielectrics has a noticeable impact on the device performance. Different high-k gate dielectrics comprised of Al2O3, Si3N4 and HfO2 are explored in our study. Moreover, when high-k gate dielectric is used instead of conventional SiO2 insulator, the electrical characteristics will be improved in terms of ION/IOFF ratio, transconductance to drive current ratio (gm/IDS) and SS. Based on our simulations and obtained results, scaling GAA-FETs by utilizing high-k dielectrics offers superior electronic devices and promising candidates for “more Moore” domain and integrated circuit applications.

In this study, the doping impact of indium (In) on the actual properties of CdO at different content of (1, 2, and 3 wt% In) was discussed. The samples were prepared utilizing the spray pyrolysis method. The structural, topographical, and optical properties were characterized X-ray diffraction (XRD) analysis, UV-Vis, and atomic force microscope (AFM). The surface topography was discussed by utilizing AFM analysis. Results display that the average diameter appears to be dependent on the indium content. The particle size was decreased from 78.05 to 65.77 nm when In content was increased from 0% to 3%. It is found that the roughness of the film was decreased to 3.03 nm via increasing In content to 3%. Also, the band gap of prepared samples were studied and compared. Results revealed that the value of band gap is decreasing via doping indium. The band gap of bare CdO, 1%In-CdO, and 3%In-CdO were determined 2.63, 2.54, and 2.46 respectively.

Nano-γ-Al2O3/BF3/Fe3O4 magnetic nanoparticles was synthesized and characterized with Fourier Transform Infrared (FT-IR), Powder X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmittance Electron Microscopy (TEM), Vibrating Sample Magnetometer (VSM), Brunauer–Emmett–Teller (BET) and Thermal Gravimetry (TGA). Dihydropyrimidinones (DHP) act as antivirals, antibacterial, antifungal, antiinflammatory, antioxidan, anticarcinogen, calcium channel blockers, antihypertensive, anti-cancer and anti-HIV compounds. Nano-γ-Al2O3/BF3/Fe3O4 magnetic nanoparticles as an efficient catalyst was applied for the mild and green one-pot multicomponent synthesis of 3,4-dihydro pyrimidine-2(1H)-ones/thiones under solvent-free conditions. Biginelli reaction proceeds through an aldehyde, β-keto ester and urea or thiourea to the dihydropyrimidinone. Excellent yields of dihydropyrmidinones are gained within a short reaction time. The proposed method offers several advantages such as short reaction time, high efficiency, smooth purification, cleaning reaction, ease of recovery, and reusable catalyst. The structure and purity of these compounds were confirmed using IR and 1H NMR and 13C NMR spectral analysis. Meanwhile, the physical property of products were compared with reported ones.

Hydrothermal synthesis of magnetic and photoluminescence CuFe2O4-carbon dots nanocomposite as a sensor for detecting of Hg(II) ionsCarbon quantum dots were prepared by using ethylene-diamine and citric acid materials. Micro-wave was applied for synthesis of copper ferrite, hydrothermal method was used as an effective method for preparation of product with preferential growth. Finally, CuFe2O4 and magnetic copper ferrite-carbon nanocomposite were synthesized. The effects of power and cycles on the morphology and particle size were investigated. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, ultra violet-visible (UV-Vis) absorption and photo-luminescence (PL) spectroscopy. The prepared product show suitable photo-luminescence under ultraviolet irradiation. Vibrating sample magnetometer (VSM) shows ferromagnetic property of the both CuFe2O4 and copper ferrite-carbon nanocomposite. The results show that this method for preparation of magnetic and luminescence nanocomposite as a candidate for sensor applications.Keywords: Carbon Quantum Dots; Nanocomposite; Magnetic; Photoluminescence

In this work, the Ni1-xCuxTiO3 (0 ≤x ≤ 0.1) ilmenite materials were successfully synthesized using the citrate-gel method using nickel nitrate, copper nitrate and titanium (IV) isopropoxide as Ni, Cu, Ti sources and citric acid as complexing reagent. The evolution of the microstructural properties was investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Powder X-ray diffraction pattern confirms the formation of the ilmenite phase for all the samples. The particle size of the prepared samples substantially increased with increase of copper dopant content. The study of phonon vibration by Raman spectroscopy identified a change in structure of NiTiO3 due to Cu dopant. The optical properties with the Cu content was carried out using UV-vis absorption spectroscopy. The reduction of optical band gap from 2.31 eV to 1.99 eV was obtained for undoped NiTiO3 and 10 mol.% Cu dopant in NiTiO3, respectively. To evaluate the photocatalyst properties of NiTiO3, the photocatalytic degradation of congo red under visible light irradiation was carried out. Our results revealed that the copper dopant into NiTiO3 lattice promoted the increase of particle size, decrease of optical bandgap and enhancement of textile photodegradation.

The production of antimicrobial sachet from silica-alginate-nanocellulose composite beads as carrier materials with the addition of nanocellulose (0, 1, 3, 5%) as nanofiller and cinnamon essential oil (CEO) as antimicrobial agent was investigated. The nanocellulose was isolated from oil palm empty fruit bunches by mechanical treatment using a combination of ultrafine grinding and ultrasonication. The produced composite beads were observed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and x-ray diffraction (XRD) analysis. The produced composite beads with 5% nanocellulose (BDCN5) was more compact and spherical than others. Meanwhile, the produced antimicrobial sachets were performed with release characteristic and antimicrobial tests. The antimicrobial sachet with the addition of nanocellulose showed the cinnamon essential oil was significantly released from beads for 60 min and had a high inhibitory effect. Almost all microorganisms tested by BDCN5 showed a high inhibitory effect, 5.43% for inhibiting Escherichia coli, 5.19% for Salmonella sp, 3.36% for Aspergillus sp, and 8.72% for Staphylococcus aureus.

In the present work, the zinc oxide nanoparticle and its composite have prepared with the graphene as a photoanode electrode as well as synthesizing an excellent thin film from the PEDOT: PSS, which is conductive polymer loading with MWCNT as an auxiliary electrode for the DSSC. The photoanode characterized using ( XRD, FTIR, Raman spectroscopy, BET-BJH, and UV-DRS). The FESEM and AFM performed to study morphology and structure of ZnO, ZnO/Graphene, and PEDOT: PSS/MWCNT thin films. The results confirm a successful fabrication of the thin films on the ITO by using the electrophoretic deposition method as well the added of graphene reduced the band gap close to 3.0eV. Moreover, the PEDOT: PSS/MWCNT nanocomposite based an auxiliary electrode offered high electrical conductivity, which enhanced the photovoltaic values of DSSC. The BET-BJH results demonstrated of the synthesis of zinc oxide nanoparticles at the surface area 6.66 m2/g and pore size 1.42 m3/g.

In this research, a new photocatalyst of TiO2/en-MIL-101 (Cr) was synthesized via hydrothermal method. The as-prepared hetrostructure material was characterized by X-ray diffraction, Fourier Transform Infrared Spectrometer, energy dispersive X-ray spectroscopy, ultraviolet-visible diffuse reflection spectra, scanning and transmission electron microscopy. The photodegradation of rhodamine B by the synthesized photocatalysts was investigated under UV irradiation and visible light. The results showed that immobilization of TiO2 on the surface and inside the photocatalytic structure enhanced the degradation of the pollutant. The band gap energy of the synthesized TiO2/en-MIL-101(Cr) measured by ultraviolet-visible diffuse reflection spectra showed that an insignificant shift to lower energy was situated after immobilization onto the structure of the supports. The relationship between the photocatalytic activity and the structure of TiO2/en-MIL-101(Cr) hetrostructure was discussed. The degradation efficiency of 84% and 77% of rhodamine B was respectively obtained by TiO2/en-MIL-101(Cr) under Uv and visible light, respectively. This work has introduced a new way for using the MOF in the design of photocatalyst substrate for organic dyes degradation in waste water.

In this study, the chemical bath deposition (CBD) strategy was applied for preparation of pure and Lithium-doped copper sulfide (CuS) thin film on glass. The CuCl2.2H2O, as a copper source and thiourea as a sulfur source were used. The structural, topographical, and optical properties of products were characterized via powder X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-Vis spectroscopy. Results showed that the crystalline size is increased via Lithium doping, though the strain (%) parameter decrease from 30.39 to 27.47. Obtained results revealed that doing of lithium has a significant effect on the optical properties of prepared CuS-based thin films. The optical properties of samples was investigated through band gap calculation. The bands gap were calculated 2.4, 2.5, and 2.6 eV for CuS:3% Li, CuS:1% Li and pure CuS thin films respectively. Based on attractive properties of prepared thin films, Lithium-doped CuS thin film has potential application in optoelectronic fields.

In this work, CoFe2O4 was synthesized as magnetic agent and blended with chitosan-poly vinyl alcohol (CS-PVA) to fabricate magnetic nanofiber (MNF) by electrospinning method. Zeolitic imidazolate framework-8 (ZIF-8) crystals were used as a porous media to prepare MNF@ZIF-8 nanocomposite. Two different methods were employed for doping copper ions into the MNF@ZIF-8 structure by adsorption and encapsulation procedures. Characterization clarification of as synthesis materials were performed. Mechanical tests showed that magnetic nanoparticles caused to improve tension resistance of CS-PVA nanofibrous scaffold. Antimicrobial tests for the prepared materials were done in against two types of Gram-positive and Gram-negative strains. The inhibition zone diameter values for Cu2+ adsorbed-MNF@ZIF-8 (33 mm and 24 mm for E.coli and S.aureus, respectively) were better than that of Cu2+ encapsulated-MNF@ZIF-8 (32 mm and 18 mm for E.coli and S.aureus, respectively). The obtained results showed that the prepared copper doped MNF@ZIF-8 can be potentially used as a scaffold for further investigations in practical wound healing applications.

In this work, SrMnO3 nanoparticles were successfully synthesized using dimethylglyoxime (DMG) and triethylenepantamine (TEPA) as capping agent and alkaline agent respectively. To achieve the desired sample with high homogeneity and the fine size, various parameters such as capping agent, alkaline agent and temperature of calcination were changed. SrMnO3 nanostructures with different morphologies such as unique sphere-like and hierarchical were successfully prepared. Then on the surface of the optimum sample, silver nanoparticles were doped. The as-synthesized nanostructures were characterized by thermal gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray microanalysis (EDX) and UV–Vis diffuse reflectance analysis (DRS). The photocatalytic degradation of the rhodamine B, methyl orange, murexide and methylene blue as water pollutants were investigated. According to the results, photocatalytic activity of SrMnO3/Ag nanostructures were better and degradation percent of rhodamine B as a cationic pollutant was more than the other dyes.

AbstractIn this study, BaFe2O4–activated clay nanocomposites were successfully synthesized via mechanosynthesis technique for the first time. Structural analysis of the products confirmed the nanoscale formation of nanocomposites. This study focused on adsorption of hydrogen sulfide (H2S) which is a poisonous gas and can be released from sewage sludge. Formation of nanocomposites was verified by scanning electron microscopy (SEM), energy dispersive X-ray (EDS) analysis, Fourier transform infrared (FTIR) and X-ray powder diffraction (XRD). Results showed that different loadings of barium ferrite in the nanocomposite were important for the adsorption rate. Furthermore, adsorption rate of hydrogen sulfide was improved by increasing BaFe2O4- activated clay concentration which was confirmed by statistical results. The highest average of removal efficiency was 92.79±0.90 in the concentration of 300 g.L-1and the loading of 6%. We could recycle BaFe2O4–activated clay nanocomposite 3 times without a significant decrease in activity. Enhanced performance of BaFe2O4–activated clay, compared to other nanocomposites, recommends its application for adsorptive desulfurization.

The present work is mainly focused on the synthesis and characterization of surfactant-assisted Ir-Sn BMNP (bimetallic nanoparticles) using modified polyol method. CTAB (Cetyltrimethylammonium bromide), TSC (Trisodium citrate), and TX-100 (Triton X-100) as cationic, anionic, and nonionic surfactant respectively are used to study their effect on the particle size, morphology, and their stability. The synthesized particles are characterized by XRD, FE-SEM, EDAX, elemental mapping, TEM, HR-TEM, XPS and FT-IR, TGA, DTG, and DTA techniques. UV-Vis spectroscopy is used to monitor the synthesis of nanoparticles. The XRD patterns of all samples confirm that Ir-Sn BMNP are amorphous in nature. The influence of surfactant on the morphology and particle size of Ir-Sn BMNP samples was examined by the FE-SEM technique. The FE-SEM figures demonstrate that the particles of bimetal are in nano size, highly dispersed, and pseudo spherical in shape with smooth surfaces. The approximate crystallite (particle/grain) size of CTAB, TSC, and TX-100 assisted samples are ~1.39 nm (39 nm), ~2.2 nm (59 nm), and ~5.79 nm (89 nm) respectively, which are estimated from TEM and FE-SEM images. The presence and distribution of Ir and Sn elements in the BMNP is determined through EDAX and elemental mapping respectively. These techniques show that CTAB assisted Ir-Sn BMNP sample is in alloy form but TSC and TX-100 samples are in core-shell form, where the Ir core is surrounded by Sn shell. The XPS confirms the metallic state (Ir0), and the dual valence state of Sn (Sn2+ and Sn4+) is in the Sn 3d core level.

Gold nanoparticles (AuNPs) were synthesis by electrolysis method as colloidal nanoparticles and deposited on both glass substrates and p-type porous silicon(PSi) to prepare films by using drop casting method to improve the performance of PS/SI solar cell. PS was prepared by electrochemical etching process (ECE) for p-Si wafers. The optical properties of PS and AuNPs were examined. The structural and morphological properties for PSi and gold nanostructure (AuNSs) deposited on glass substrate have been studied by using (XRD) and Atomic Force Microscope (AFM) respectively. TEM testing for AuNPs was investigated. XRD pattern of PSi showed that it had single crystalline structure, whereas for Au nanostructure it was polycrystalline one. AFM confirmed the nanometric size of both AuNSs and PSi it was around 40 nm for AuNSs and 62 nm for PS. The AuNPs diffusion effect on the electrical properties of PS/Si heterojunction was studied . The photovoltaic characteristics of AuNPs/PS/Si/Al Solar cell were reported and the efficiency of solar cell was 15.67% and F.F is 34.31%.

In this experimental investigation, a simple and efficient technique is presented for the carbonic nanostructures fabrication-in particular, Graphene Oxide (GO) and Graphene nanosheets- based on the pulsed laser ablation of graphite target inside the Cetyltrimethylammonium bromide (CTAB) (0.1 M) and liquid nitrogen environments using the pulsed nanosecond Q-switched Nd:Y3Al5O12 (Nd:YAG) laser at 532 nm. X-ray diffraction (XRD) pattern, Raman spectrum, Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Field emission scanning electron microscopy (FE-SEM) were used to characterize the ablation products. Results exhibit that the graphene nanosheets produced in liquid nitrogen medium are multilayer, includes the largest SP2 domain size and the least structural defects. In addition, two categories of graphene nanosheets and carbon nanoparticles were observed in TEM images of produced sample in this cryogenic medium. Furthermore, XRD, FT-IR and Raman analyses indicate that graphene is oxidized in CTAB solution owing to existence of oxygen molecules in ablation environment. Our experimental results can be useful guidance toward the production of graphene nanosheets with desired attributes.