Zno Nanoparticles Research Papers - Academia.edu (original) (raw)

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- ZnO (Zinc Oxide), Zno Nanoparticles

In the present work, Co 2þ ion doped zinc oxide nanoparticles Zn 1Àx Co x O (x ¼ 0.00, 0.06, 0.12, 0.18, 0.24, 0.30 and 0.36 mol) were synthesized by sol-gel auto combustion method. The effects of heavily doped Co 2þ ion concentration on the structural, electrical and dielectric properties were studied. The prepared nanoparticles were characterized by X-ray diffraction technique (XRD), transmission electron microscopy (TEM), selected area diffraction pattern (SAED) and Fourier transform infrared spectroscopy (FT-IR). The X-ray diffraction analysis revealed the formation of single phase having hexagonal wurtzite structure along with secondary phase (Co 3 O 4). TEM analysis clearly showed the small agglomeration and spherical shape of nanoparticles. SAED pattern also confirms the hexagonal wurtzite structure with single crystalline nature. FTIR analysis showed the vibrational frequency band position of ZneO shifted to higher frequency band with Co 2þ ion increasing host semiconductor nanoparticles. The temperature dependent (300e400 K) DC resistivity of samples was studied by the standard two probe method. DC electrical resistivity was found to increase with increasing Co 2þ content in ZnO matrix. The dielectric properties of pure and Co 2þ doped ZnO nanoparticles were studied as a function of frequency and composition using the LCReQ meter. All the dielectric parameters show dispersion and decreases with increase in Co 2þ content. The observed dielectric behavior is explained on the basis of MaxwelleWagner model and Koops phenomenological theory.

- by Shankar D Birajdar
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- Spinel Ferrite, Zno Nanoparticles

Narrow band gap zinc oxide (ZnO) nanoparticles (NPs) were synthesized using unboiled and boiled leaf extracts of Costus woodsonii. The as-synthesized NPs were characterized using a range of techniques. The as-synthesized ZnO NPs were crystalline with a hexagonal wurtzite structure similar to the commercial ZnO (ZnO-C). The maximum absorbance was observed at ~390 nm for ZnO-C and the as-synthesized ZnO NPs (ZnO-UL and ZnOBL) showed a red shift, i.e. ~448 nm to ~462 nm, hence, a lower band gap of ~2.68–2.77 eV. The band gap energy of the as-synthesized ZnO NPs was lower than that of commercial ZnO. The surface of ZnO was coated/modified with the components of the leaf extract. The as-synthesized ZnO NPs showed similar particle sizes and were spherical in shape. These studies confirmed the green synthesis of ZnO NPs using Costus woodsonii and the significantly reduced band gap (Eg =~2.68 eV to ~2.77 eV) of the as-synthesized ZnO NPs compared to the ZnO-C (Eg =3.18 eV).

ZnO nanoparticles doped with different Eu 3+ percentages were synthesized in water (ZnO:Eu(x%)-W) and other solvents (methanol ZnO:Eu(x%)-M and ethanol ZnO:Eu(x%)-E). X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), optical absorption and photolu-minescence (PL) spectroscopy were used for characterization of the nanoparticles. Our results showed influence of europium doping and solvents on size, particles agglomeration, light absorption and photo-catalytic activity. Improvement in photocatalytical activity with addition of Eu 3+ doping was detected. Particle size increased with Eu 3+ doping in water samples, while it decreased in methanol. Agglomeration was more prominent in ZnO:Eu(x%)-W samples. Greater amount of surface OH groups in case of ZnO:Eu(x%)-M samples was detected by PL, XPS and FTIR measurements. Influence of europium doping, as an electron trap, and surface OH groups, as a hole trap, was studied in sunlight photocatalytic degradation of cationic methylene blue (MB) and anionic methyl orange (MO). Improved photocatalytic behavior was discussed and influence of active species was further investigated using hole and hydroxyle radical scavengers. The degradation pathway of MB and MO, using high performance liquid chromatohraphy (HPLC), is also examined.

The zinc oxide nanomaterials (ZnO-NMs), owing to their broad biomedical applications have lately attracted the incredible interest in the development of therapeutic agents against microbial infections. In this contribution, we have biosynthesized ZnO-NMs with a size of˜40of˜of˜40 nm from the Bougainvillea flower extracts. The FTIR and SEM-EDX mapping analysis confirmed the size, shape and biogenic origin of ZnO-NPs. Furthermore, the purified ZnO-NMs were applied for antibacterial studies against susceptible and resistant bacterial strains and to elucidate the possible mechanism of their activity. The XTT assay and confocal imaging confirmed the ZnO-NMs materials anti-biofilm activities against medically important pathogens, i.e., S. aureus and E. coli. Moreover, the absence of cytotoxicity against healthy kidney cells (HEK-293) and erythrocytes confirmed their biocompatible nature. Furthermore, the biosynthesized ZnO-NMs showed potent anticancer activity against the breast cancer cell line (MCF-7). These biosynthesized ZnO-NMs are having excellent antimicrobial and anticancer activities and are highly biocompatible due to biogenic nature. During antimicrobial study, Zno-NMs showed excellent minimum inhibitory concentration 16 μg concentration againt E. coli, P. aeruginosa and S. aureus. While in anticancer activity, of ZnO-NMs with 15 μg/ml dose showed good response against MCF-7 cell line. Further, this killing was mechanically confirmed by ROS generation by the ZnO-NMs, which cause cell lysis by the peroxidation of membrane lipid. So, this biogenic ZnO-NMs can be used in the future for nanomaterial-based drug development.

- by Oves M.
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- Herbal Anticancer, Bougainvillea Flower, Antibacterial, Zno Nanoparticles
- by Hoàng Khoa Bùi
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- Nanotechnology, Nanoscience, XRD, Khoa Hoc

The use of biomass for functional nanomaterial is fascinating. Costus woodsonii was used as a green approach to synthesize zinc oxide (ZnO) nanoparticles from its bulb (flower). The as-synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), and transmission electronmicroscopy (TEM). XRD showed that the commercial ZnO (C-ZnO) and as-synthesized ZnO nanoparticles were of high purity and displayed a hexagonal wurtzite and well crystalline structure. XPS confirms that Zn was in the + 2 chemical state. FT-IR spectroscopy showed some additional peaks on the as-synthesized ZnO only due to a surface coating of the components of the bulb extract. TEMrevealed the morphology, particle size, and high purity of the ZnO nanoparticles. The UV-Vis DRS of the as-synthesized ZnO showed a red shift compared to C-ZnO, which was attributed to the surface coating of the as-synthesized ZnO nanoparticles. These studies confirmed the synthesis of ZnO nanoparticles with a lower band gap, i.e., Eg = 2.66–2.79 eV. Therefore, phytogenic synthesis could be a new or alternate pathway for the synthesis of different types of novel nanomaterials with unique characteristics without altering the basic and fundamental structure.

Pure and Cu-doped zinc oxide (ZnO) nanoparticles were prepared using a chemical method. The dopant concentration (Cu/Zn in atomic percentage (wt%)) is varied from 0 to 3 wt%.
Structural characterization of the samples performed using X-ray diffraction (XRD) confirmed that all the nanoparticles of zinc oxide are having polycrystalline nature. Morphological studies were conducted using field emission scanning electron microscopy (FESEM) to confirm the grain size and texture. Electrical measurements showed that the AC conductivity initially decreases and then rises with increasing Cu concentration. The UV–Vis studies showed absorbance peaks in the 200– 800 nm region. It is found that the absorbance does not significantly change with doping. This fact is further confirmed from the band-gap calculations using the reflectance graphs. When analysed in terms of Burstein–Moss shift, an increase of band gap from 3.42 to 3.54 eV with increasing
Cu concentration is observed. In the photoluminescence (PL) studies a red-shift is observed with increasing dopant concentration.

- by Arindam Ghosh
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- Zno Nanoparticles

The management of contaminants of emerging concern (CECs) in water bodies is particularly challenging due to the difficulty in detection and their recalcitrant degradation by conventional means. In this review, CECs are characterized to give insights into the potential degradation performance of similar compounds. A two-pronged approach was then proposed for the overall management of CECs. Light-driven oxidation processes, namely photo/Fenton, photocatalysis, photolysis, UV/Ozone were discussed. Advances to overcome current limitations in these light-driven processes were proposed, focusing on recent trends and innovations. Light-based detection methodology was also discussed for the management of CECs. Lastly, a cost–benefit analysis on various light-based processes was conducted to access the suitability for CECs degradation. It was found that the UV/Ozone process might not be suitable due to the complication with pH adjustments and limited light wavelength. It was found that EEO values were in this sequence: UV only > UV/combination > photocatalyst > UV/O3 > UV/Fenton > solar/Fenton. The solar/Fenton process has the least computed EEO < 5 kWh m−3 and great potential for further development. Newer innovations such as solar/catalyst can also be explored with potentially lower EEO values.

- by brandon lee and +2
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- Advanced Oxidation Processes, Water and wastewater treatment, Ozonation, Fate and Transport of Emerging Contaminants

A B S T R A C T Nowadays, medical textiles have become the most essential and developing part in human healthcare sector. This work was undertaken with a view to harness the bio-active macromolecules secreted by fungi e.g. proteins and enzymes in bio-synthesis of ZnO nanoparticles for multifunctional textiles such as antibacterial activity and UV protection with considering the cytotoxicity limitation. Herein, the isolated fungus, Aspergillus terreus, was allowed to produce proteins which has affinity to cape ZnO-NPs. Various factors affecting the behavior of the secreted proteins on the formed nanoparticles were investigated. Thorough characterizations of the protein capped ZnO-NPs were performed by the using of UV–Visible spectroscopy, transmission electron microscope (TEM) Fourier Transform-Infra Red (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis and Dynamic light scattering analysis (DLS). Prior treatment of cotton fabrics with ZnO-NPs, the cytotoxicity of the protein capped ZnO-NPs was examined. After that, the antibacterial activity of the ZnO-NPs before and after treating of cotton fabrics, besides, the UV-protection (UPF) properties were investigated. Results obviously demonstrated the ability of the bio-secreted protein to cape and reduce ZnO to spherical ZnO-NPs with particle size lied around 10–45 nm, as indicated form UV–vis., spectra TEM, Zeta sizer, FTIR and XRD. Regarding to the results of cy-totoxicity, the treatment of the cotton fabrics with ZnO-NPs were performed at safe dose (20 ppm). At this dose, ZnO-NPs loaded samples exhibited reasonable antibacterial activity against both Gram positive and Gram negative bacteria; besides, good UV-protection with reasonable increase in UVA and UVB blocking values. Indeed, nanotechnology based microbiological active molecules opens up new opportunities for us to explore novel applications in terms of green technology.

- by Salem Salah Salem
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- Synthesis of nanoparticles, Nanotechnology, Zno Nanoparticles

ZnO nanoparticles have been proved to be promising in cancer treatment, including the tumor cells destruction with minimal damage to the healthy cells. In the present study highly pure ZnO nano particles with a narrow size distribution of 16-19 nm were prepared by the simple DMC (Dry Mechano-Chemical) method in the lab. The anticancer activity on MCF7 (Breast cancer cell) and A549 (Lung Cancer cell) were determined by the MTT (Methylthiazolydiphenyl-tetrazolium bromide) assay. A549 and MCF-7 cells were exposed to ZnO-NPs and it exhibited 50% reduction at a very low concentration 31.2 μg/ml. Thus, the reduction in cell viability with NPs induces cytotoxicity in cancerous cells. There is a size dependent effectiveness of ZnO nanoparticles in the removal of cancer cells and also a positive correlation with reduced toxicity.

Doped and undoped specimens of nano-particulate ZnO with 0.5 wt% and 1 wt% ruthenium were prepared through a chemical route. Structural characterization of the samples performed with XRD established that all the nanoparticles are of zinc oxide having polycrystalline nature. Morphological studies were conducted using FESEM to confirm the grain size and texture. Electrical measurements showed that the ac conductivity increases with frequency but decreases with increasing ruthenium concentration, making it a potential option for device applications. It is found that the absorbance does not significantly change with doping. The above fact is further confirmed from the bandgap calculations using the reflectance graphs. A decrease of bandgap from 3.42 to 3.19 eV with increasing Ru concentration is observed making it an important and advantageous material for potential visible light photocatalytic applications involving metal oxide nanostructures.

In this paper, PMMA/ZnO nanocomposites have been prepared by a very simple, facile and versatile chemical approach. The prepared PMMA/ZnO nanocomposites possess no color, high transparency, good thermal stability, UV-shielding capability, luminescence and homogeneity. The chemical process involved solution mixing of ZnO nanoparticles dispersed in DMAc with the Polymethylmethacrylate (PMMA) matrix dissolved in the same solvent. The effect of ZnO content on the physical properties of the PMMA matrix is investigated by X-ray diffraction, field emission scanning electron microscopy, thermogravimetric analysis, UV–Vis absorption and photoluminescence spectroscopy. It was found that pure hexagonal ZnO nanoparticles with an average particle size of 4–8 nm were homogeneously dispersed in the PMMA matrix. A significant improvement in thermal properties was observed with the incorporation of 1.0 wt% ZnO nanoparticles. The prepared nanocomposite films are highly transparent and a clear excitonic peak is observed in their absorption spectra. Measurement of room temperature photoluminescence spectra shows intensive near-band edge emission peak at 3.28 eV without any structural defects for a nanocomposite film with a filler content of 1.0 wt%.

- by Majid Khan
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- Polymer Nanocomposites, PMMA, Polymer Nano Composite, ZnO (Zinc Oxide)

A cost-effective phytogenic fabrication of zinc oxide (ZnO) and copper-doped zinc oxide (Cu-doped ZnO) using aqueous leaf extract of Ziziphus mauritiana Lam. was successfully demonstrated. The structural, morphological and optical studies have been carried out using various techniques. XPS, XRD analysis and FT-IR spectroscopic studies confirmed the successful synthesis, crystalline nature and purity of synthesized ZnO and Cu-doped ZnO. UV–visible diffuse reflectance spectra showed reduction of band gap energies from 3.11 to 2.54 eV as Cu doping increases from 0% to 5%. SEM images revealed the synthesized ZnO and Cu-doped ZnO are irregular and spherical shaped, respectively. Antibacterial property of the synthesized materials were evaluated against Gram positive Staphylococcus aureus and Gram negative Escherichia coli using different concentrations. This investigation revealed that the synthesized materials were able to inhibit the activity of Staphylococcus aureus better than Escherichia coli under both dark and visible light conditions with the highest inhibition of 9.33 ± 0.58 mm under light irradiation. The synthesized materials were also found to effectively scavenge 2,2-diphenyl-1-picrylhydrazyl radicals in the dark and an enhancement of the scavenging activity was observed under visible light irradiation.

Zinc oxide (ZnO) is considered as a potential antimicrobial agent. This work aims to investigate the properties of ZnO and Mn-doped ZnO (1% and 5%) fabricated using aqueous leaf extract of Melastoma malabathricum via green synthesis and its antibacterial activities. The synthesized ZnO and Mn-doped ZnO were characterized using different techniques such as powder X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV-Vis diffuse reflectance spectroscopy. The synthesized ZnO and Mn-doped ZnO were tested for its antibacterial properties on two Gram-negative bacteria: Escherichia coli and Pseudomonas aeruginosa, and two Gram-positive bacteria: Bacillus subtilis and Staphylococcus aureus. The results showed positive antibacterial effects for B. subtilis and S. aureus only. Among the three materials tested, 1% Mn-doped ZnO exhibited the highest antibacterial activity for B. subtilis with the minimum inhibitory concentration being 50 mg/mL.

- by Prof. Dr. Mohammad Mansoob Khan
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- ZnO nanorods, ZnO (Zinc Oxide), Zno Nanoparticles
- by Mohammed El-Kereti
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- Fertility, Medicinal Plants, Nanotechnology, Plant Anatomy

In this study, pure ZnO, CeO2 and ZnO/CeO2 nanocomposites were synthesized using a thermal decomposition method and subsequently characterized using different standard techniques. High-resolution X-ray photoelectron spectroscopy measurements confirmed the oxidation states and presence of Zn2+ , Ce4+ , Ce3+ and different bonded oxygen species in the nanocomposites. The prepared pure ZnO and CeO2 as well as the ZnO/CeO2 nanocomposites with various proportions of ZnO and CeO2 were tested for photocatalytic degradation of methyl orange, methylene blue and phenol under visible-light irradiation. The optimized and highly efficient ZnO/CeO2 (90:10) nanocomposite exhibited enhanced photocatalytic degradation performance for the degradation of methyl orange, methylene blue, and phenol as well as industrial textile effluent compared to ZnO, CeO2 and the other investigated nanocomposites. Moreover, the recycling results demonstrate that the ZnO/CeO2 (90:10) nanocomposite exhibited good stability and long-term durability. Furthermore, the prepared ZnO/CeO2 nanocomposites were used for the electrochemical detection of uric acid and ascorbic acid. The ZnO/CeO2 (90:10) nanocomposite also demonstrated the best detection, sensitivity and performance among the investigated materials in this application. These findings suggest that the synthesized ZnO/CeO2 (90:10) nanocomposite could be effectively used in various applications.

- by Prof. Dr. Mohammad Mansoob Khan and +2
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- Nanomaterials Characterization, Nanomateriala Characterization, Nanocomposites, Nanomaterials

ZnO nanoparticles assisted with ethanol and 2propanol as capping agent investigated the medical activities of
ZnO nanoparticles and ZnO/Ag composite. ZnO nanoparticles were prepared using zinc acetate and silver nitrate
as a source of zinc and silver. ZnO/Ag composite also prepared and studied the medical activities. XRD pattern
indicates that the structure of ZnO was hexagonal wurtzite with average size 5 nm according to Scherre's
formula. The optical band gap of ZnO nanoparticle showed very sensitive for using different capping agent as
shown in UV-VIS spectra and also showed blue shift in wavelength corresponding to capping agent. Finally, the
antibacterial properties of ZnO and ZnO/Ag composite against Gram-negative and Gram-positive bacteria have
been demonstrated using well diffusion method and indentify their antibacterial effects compared with organic
antibacterial agents.

- by mukhlis ismail
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- Zno Nanoparticles, Optical Energy Gap, Antibacterial Silver
- by Md. Abul Kalam
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- Engineering, Mechanical Engineering, Materials Science, Performance Studies

Optical, electrical and sensing properties of ZnO nanoparticIes, prepared by sol-gel process and subsequent dried in supercritical conditions, are presented. To investigate the morphological and microstructural properties, transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV-visible spectroscopy and (PL) spectroscopy analysis have been used. From microstructure analysis we showed that pure ZnO nanoparticIes were polycrystallines and exhibited the hexagonal wurtzite . Chemoresistive sensor consisting of a thick layer of ZnO nanoparticIes annealed at 400°C for 2h in air on interdigitated alumina substrate has been fabricated and its electrical and sensing characteristics were investigated. The sensor
performances towards carbon monoxide (CO) with and without UV illumination were reported. An increase of sensitivity, along a reduction of ZnO thick film resistance, was observed when the sensor operates under UV irradiation.

- by OMRI Karim and +1
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- Nanomaterials, Zno Nanoparticles

Rapid transmission of infectious microorganisms such as viruses and bacteria through person-to-person contact has contributed significantly to global health issues. The high survivability of these microorganisms on the material surface enumerates their transmissibility to the susceptible patient. The antimicrobial coating has emerged as one of the most interesting technologies to prevent growth and subsequently kill disease-causing microorganisms. It offers an effective solution a non-invasive, low-cost, easy-in-use, side-effect-free, and environmentally friendly method to prevent nosocomial infection. Among antimicrobial coating, zinc oxide (ZnO) stands as one of the excellent materials owing to zero toxicity, high biocompatibility to human organs, good stability, high abundancy, affordability, and high photocatalytic performance to kill various infectious pathogens. Therefore, this review provides the latest research progress on advanced applications of ZnO nanostructure-based antibacterial coatings for medical devices, biomedical applications, and health care facilities. Finally, future challenges and clinical practices of ZnO-based antibacterial coating are addressed.

In this paper, a novel electrochemical sensor based on flower shaped Zinc Oxide (ZnO) nanoparticles for the determination of dopamine is reported. Flower shaped ZnO nanoparticles is synthesized by a new aqueous solution method without the use of any shape directing reagents and the verification of its successful formation is carried out by scanning electron microscope (SEM) and X-ray diffraction analysis (XRD). Cyclic Voltammetry (CV), Differential Pulse voltammetry (DPV) and amperometric (i-t) techniques are used to study the electrochemical characteristics of flower shaped ZnO nanoparticles. In this study, the lower oxidation potential and higher oxidation peak current of flower shaped ZnO modified glassy carbon electrode (GCE) indicates that its electrocatalytic activity is better than bare GCE in the oxidation of dopamine. Even in the presence of common interfacing compounds, the modified GCE exhibited excellent selectivity which is a trait of good electrochemical sensor. The linear response range of the fabricated electrochemical sensor based on flower shaped ZnO nanoparticles is 0.1-16 µM, limit of detection is 0.04 µM and the sensitivity is 4.38 µAµM-1 cm-2. The low detection limit, excellent sensitivity and wide linear response range signified the efficiency of flower shaped ZnO nanoparticles based electrochemical sensor for the detection of dopamine.

- by Deepak Balram and +2
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- Sensor, Scanning Electron Microscopy, Nanotechnology, Electrochemical Sensors

ZnO nanomaterials with controlled size, shape and surface chemistry are required for applications in diverse areas, such as optoelectronics, photocatalysis, biomedicine and so on. Here, we report on ZnO nanostructures with rod-like and spherical shapes prepared via laser ablation in liquid using a laser with millisecond-long pulses. By changing laser parameters (such as pulse width and peak power), the size or aspect ratio of such nanostructures could be tuned. The surface chemistry and defects of the products were also strongly affected by applied laser conditions. The preparation of different structures is explained by the intense heating of liquid media caused by millisecond-long pulses and secondary irradiation of already-formed nanostructures.

- by Sergei Kulinich
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- ZnO nanorods, Zno Nanoparticles, Laser Ablation in Liquids

In cereal crops Zinc (Zn) deficiency has become a major problem which causes reduction in yield and nutritional quality of the cereal grain, thus affecting human health. Being an essential micronutrient for the production of rice (Oryza sativa L.) crop, Zn deficiency appears to be an acute problem for the human population whose staple food is rice. Small increase in the nutritive value of rice can thus contribute to the human nutrition. Thus, increasing the micronutrient content of a food crop with the help of enriched fertilizers appears to be an effective way. During two successive growing seasons (wet season, 2017 and dry season, 2018) at the experimental farm of PalliSiksha Bhavana, Visva-Bharati, West Bengal, India, field experiments were carried out to assess the potential of Zn fertilizer on plant height, grain quality, leaf chlorophyll and leaf Zn content of rice plant variety MTU-1010 by application of foliar Nano-ZnO (Zinc oxide) and soil ZnSO4.7H2O (Zinc Sulphate Hepta Hydrate). In both seasons, each experiment was conducted in a randomized block design (RBD) with three replicates. Soil Zn as ZnSO4.H2O applications were assigned in the plots at the rate of 5 kg/ha and 0.30% nano-ZnO were assigned as foliar Zn spray along with the basal doses of 80 kg nitrogen (N), 40 kg phosphorus (P2O5) and 40 kg potassium (K2O)/ha as per the treatment details. After 15 days, 30 days, 45 days from transplanting and at the time of flowering as well as post-flowering chlorophyll (a, b, a+b) and Zn in rice plant leaves were determined. Plant heights were recorded after 30 days, 60 days and 90 days from transplanting and at the time of harvest. Quality parameters such as amylose, starch and crude protein content of the grain samples were determined at harvest stage. The results obtained from present assessment showed that, application of soil as well as foliar Zn resulted in significant increase in leaf Zn content, chlorophyll content, grain crude protein and plant height compared to the control. No significant effect on starch and amylose was recorded with Zn fertilization. Foliar spraying with 0.30% nano-ZnO at the time of flowering and post flowering showed a significant augmentation in leaf Zn concentration, chlorophyll content, plant height and quality of rice grain compared to the treatments receiving soil Zn application. Therefore, it is considered as a more beneficial treatment in the cultivation of rice plants to promote plant growth and quality.

- by SUNANDANA MANDAL
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- Zno Nanoparticles, Rice Cropping System, Zno Nano - Fertilizer, ZnSO4

With the help of microwave-assisted technique, zirconia (ZrO 2) nanocrystalline powder was synthesized using a structure directing agent which could be controlled by the nucleation and particle growth. The various characterizations, namely, phase, surface morphology, surface area analysis and optical property were carried out by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and UVevisible spectroscopy. From XRD analysis, it was found that the synthesized materials reveal the tetragonal crystalline phase. The average particle size of ZrO 2 was found 14.7 nm by TEM. Specific surface area, pore volume and the pore size for ZrO 2 are 220 m 2 /g, 0.02 cm 3 /g and 10.7 nm investigated by BET, respectively. UVevis DRS spectra of the prepared material confirmed that the Zr atoms are exclusively incorporated within silica framework. Besides, the maximum absorption peaks were observed at 215 nm and 217 nm for as-synthesized and calcined samples, respectively.

- by Dr. Manikandan Elayaperumal and +1
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- ZnO,TiO2 nanowires, ZnO, SnO2, CuO and Si Nanowires, ZrO2 SO4, Zno Nanoparticles

ZnO nanoparticles with particle size less than 50nm are synthesized by simple sol gel method. These nanoparticles can be used as a source layer for the extraction of electrons in heterojunction organic solar cells. Zinc acetate is used as a precursor material in this case. X-Ray powder Diffraction, Ellipsometery and Scanning Electron Microscopy are used to study the crystal structure, optical properties and surface morphology of the synthesized nanoparticles, respectively. The presence of (100),
(002) and (101) planes in the XRD graphs strongly indicates that ZnO has wurtzite structure even under as-synthesized conditions. Surface morphology was studied by SEM which indicates that the nanoparticles are of spherical shape with size less than 100 nm. Large area growth of these nanoparticles is also observed with uniform size distribution. A remarkable decrease in the transmission values is observed by increasing the pH from 2 to 9. Refractive index ~ 1.5 is observed at 350nm for all of the samples except the one synthesized with pH 9.

- by Shahzad Naseem
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- Zno Nanoparticles
- by ALWAN NASAIF
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- Sol-Gel, Zno Nanoparticles

Particle size dependent anti-bacterial and anti-diabetic activities of green synthesized ZnO nanoparticles.

The antibacterial effect of zinc oxide (ZnO#1) as prepared and annealed (ZnO#2) at 400 o C, Cu doped ZnO (CuZnO), and Ag doped ZnO (AgZnO) nanoplates on Staphylococcus epidermidis was investigated for the inhibition and inactivation of cell growth. The results shows that pure ZnO and doped ZnO samples exhibited antibacterial activity against S. epidermidis as compared to tryptic soy broth (TSB). Also it is observed that S. epidermidis was extremely sensitive to treatment with ZnO nanoplates and it is clear that the effect is not purely depend on Cu/Ag. Phase identification of a crys talline material and unit cell dimensions were studied by Xray powder diffraction (XRD). The scan ning electron microscopy (SEM) provides information on sample's surface topography and the EDX confirms the presence of Zn, O, Cu and Ag. Xray photoelectron spectroscopy (XPS) was used to analyze the elemental composition and electronic state of the elements that exist within the samples. These studies confirms the formation of nanoplates and the presence of Zn, O, Ag, Cu with the oxida tion states +2, 2, 0 and +2 respectively. These results indicates promising antibacterial applications of these ZnObased nanoparticles synthesized with lowcost hydrothermal methods.

- by Joshua Pearce
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- Materials Engineering, Materials Science, Biomaterials, Nanomaterials

A simple, rapid and sensitive method was developed using ZnO nanoparticle (ZnO-NP) amplified flow-injection chemiluminescence to detect carvedilol, a non-cardioselective β-blocker. It has been found that carvedilol strongly inhibits the chemiluminescence of luminol–H 2 O 2 catalyzed by ZnO-NPs. Under optimum conditions, a linear working range for carvedilol concentrations from 5 Â 10 À 8 to 1.0 Â 10 À 6 mol L À 1 (r4 0.9894, n ¼ 8) was obtained with a detection limit of 3.25 Â 10 À 9 mol L À 1. The relative standard deviation for 8 repetitive determinations was less than 2.9% and recoveries of 99% and 102% were obtained. ZnO-NPs were synthesized using a green mechanochemical route. Transmission electron microscopy and x-ray diffraction were used to characterize ZnO-NPs. The method was successfully applied to detect carvedilol in pharmaceutical formulations.

- by Izodora Spataru
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- Chemistry, Nanotechnology, Nanocatalyst, Nanoscience

Glucose oxidase was immobilized using a poly
(hydroxyethylmethacrylate)-based hydrogel composite material
containing polyethylene glycol and cross-linked with
tetraethyleneglycol diacrylate onto a ZnO-modified microdiamond
biosensor. The ZnO-modified biosensor was grown by
hydrothermal decomposition on array of gold patterned microdiamonds
with an electroactive area of 18.8 mm2. The morphology
of the ZnO-modified electrode was characterized by scanning
electron microscope. A potential of +0.7 V versus Ag/AgCl
reference electrode was applied to the biosensor. The hydrogel
composite ZnO-modified microdiamond biosensor exhibited a
linear dynamic range from 0.01 to 15 mM and a reproducible
sensitivity of 31.4 μA/mM cm2. The experimental detection limit
was 0.01 mM with a rapid response time of <2 s.

- by Joshua Sunday and +1
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- Biosensors, ZnO (Zinc Oxide), Continuous Glucose Monitoring, Zno Nanoparticles

Particle size dependent anti-bacterial and anti-diabetic activities of green synthesized ZnO nanoparticles.

ZnO nanoparticles (NPs) with tunable morphologies were synthesized by a hybrid electrochemical–thermal method at different calcination temperatures without the use of any surfactant or template. The NPs were characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction, dynamic light scattering, thermogravimetry–differential thermal analysis, scanning electron microscope and N 2 gas adsorption–desorption studies. The FT-IR spectra of ZnO NPs showed a band at 450 cm-1 , a characteristic of ZnO, which remained fairly unchanged at calcination temperatures even above 300 °C, indicating complete conversion of the precursor to ZnO. The products were thermally stable above 300 °C. The ZnO NPs were present in a hexagonal wurtzite phase and the crys-tallinity of ZnO increased with an increasing calcination temperature. The ZnO NPs calcined at lower temperature were mesoporous in nature. The surface areas of ZnO NPs calcined at 300 and 400 °C were 51.10 and 40.60 m 2 g-1 , respectively, which are significantly larger than commercial ZnO nanopowder. Surface diffusion has been found to be the key mechanism of sintering during heating from 300 to 700 °C with the activation energy of sintering as 8.33 kJ mol-1. The photocatalytic activity of ZnO NPs calcined at different temperatures evaluated by photocatalytic degradation of methylene blue under sunlight showed strong dependence on the surface Electronic supplementary material The online version of this article (

- by Mohammad Shohel and +1
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- Water and wastewater treatment, Photocatalysis, Porous Structure of Catalysts, Calcination
- by Dr. Souad El-Feky
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- Biomass, Fertility, Nanoparticles, Medicinal Plants

In the present study, phenanthrene degradation by yeast Candida tropicalis NN4 was optimized in the presence of biogenically synthesized ZnO nanoparticle using plant extract of Ocimum tenuiflorum and produced biosurfactant in the medium. The biosynthesized ZnO nanoparticles were characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and Transmission Electron Microscopy (TEM) analysis. Biosurfactant producing ability of the yeast isolate was investigated by drop collapse test, emulsification index, methylene blue agar plate method, oil displacement test and lipase activity. The type of biosurfactant produced was sophorolipid which was characterized by FT-IR analysis. Response surface methodology (RSM), threelevel three variables Box Behnken Design (BBD) were employed to optimize the factors viz., pH (7), NaCl concentration (1.5 gL-1) and ZnO nanoparticle concentration (0.02gL-1) for maximum phenanthrene degradation using C. tropicalis NN4. The TEM micrograph illustrated that the biosynthesized ZnO nanoparticle exhibited different nanostructures viz. tetragonal, spherical, hexagonal and triangular shaped with the average core diameter of 20 nm. The actual value (86.5 ± 0.02%) was in close agreement with predicted value (86.5 ± 0.01%) obtained by the RSM model indicating the validity of the RSM model. Phenanthrene degradation was confirmed through FTIR and GC-MS analysis. These results support the effectiveness of using RSM for maximum phenanthrene degradation.

In this study, we report soft and solvothermal methods for synthesis of zinc oxide nanoparticles (ZnO NPs). Both methods involve a precursor and are carried out at the middle low-temperature regime. The effect of different solvents on the ZnO NPs properties was studied. The nonlinear optical (NLO) response of the NPs was analyzed by the self-action of picosecond laser pulses at 1064 nm and by second harmonic generation (SHG) of a femtosecond laser pulses pump at 800 nm. The luminescence was studied within UV-visible ranges. It was shown that the NLO response efficiency significantly depends on the solvent. The obtained SHG efficiency of small (~2 nm) ZnO NPs is comparable to the one obtained for large (~150 nm) commercial ZnO NPs. The observed results are important for the application of the ZnO NPs in biolabeling.

- by Volodymyr Gayvoronsky and +2
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- Second Harmonic Generation, Hydrolysis, Zno Nanoparticles, Nonlinear optical response
- by Sheikh Akbar
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- Engineering, Digital Fabrication, Economic Growth, Photoluminescence

zinc oxide nanoparticles have been synthesized using nigella sativa L. seed extract. Nigella sativa L. is an annual herbaceous plant belonging to the Ranunculaceae family. Concentration of plant extract plays a vital role in the synthesis of nanoparticles zinc oxide. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). This experiment was conducted in Arak University in an experiment based on randomized complete block design with four replications. Each replication consisted of one fertilizer levels including 2 per thousand of Zn-nanoparticles in one stages of growth (8 or 12 leaves). During the experiment, the height of plant, number of branches was investigated. This study showed that using spraying had significant differences in the factors like plant height number of branches. Also, using all microelement treatments had significant effects to the level of 1%. In case of using spraying treatments, the best results for number of branche...

- by Shahab Khaghani
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- Materials Science, Chemistry, Medicinal Plants, Nanotechnology

Both coherent Third Harmonic Generation (THG) at the interfaces of a cuvette filled with a nanocrystal suspension and incoherent Second and Third Harmonic Scattering (THS) from the suspension volume have been studied to quantitatively assess the orientation-averaged third-order susceptibility χ NPs (3) of ZnO. These two complementary experimental approaches are based on different calibration routes with a nanocomposite model and fused-silica as a reference material for THG, and pNa molecules for THS. Similar and consistent absolute values of χ NPs (3) (above − 10 18 m 2 /V 2) are derived and discussed according to the particular orientation averaging procedure that holds for each experimental configuration for a 1064 nm excitation wavelength.

- by Volodymyr Gayvoronsky
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- Zno Nanoparticles, Third Harmonic Generation
- by Yasuhiko HAYASHI
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- Graphene, Nanocomposites, Zno Nanoparticles

In this work, zinc oxide (ZnO) nanoparticles were synthesized by simple chemical precipitation method in the present of zinc nitrate as zinc precursor and sodium hydroxide as hydroxide precursor. The vitamin C was used as modifier media to modify the structural properties of ZnO nanoparticles. The microstructures of ZnO nanoparticles were characterized by field emission scanning electron microscope (FE-SEM) and transmission electron microscope (TEM). Selected area electron diffraction (SAED) patterns showed that polycrystalline hexagonal phase of ZnO. The defects and impurity contents in nanoparticles were investigated by Fourier transform infrared (FT-IR) spectroscopy. The results show few carboxylate and hydroxyl impurities for larger particles when addition modifier increases. Surface areas of nanoparticles were measured by
Brunauer Emmett Teller (BET) method. In addition, the results exhibited the dramatically change in structural properties of ZnO nanoparticles due to the effect of vitamin C.

- by swarup majee
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- Nanotechnology, Nanoscience, Conduction Mechanism, Dielectric Properties

Two facile and efficient methods, to synthesize zinc oxide
(ZnO) particles with different morphologies, have been reported
here. Thermal decomposition route yielded micron
sized irregular shaped ZnO particles. While co-precipitation
method rendered transparent flakes which then transformed
to hexagonal discs with relatively more uniform size
and shape. These hexagonal discs were further converted to
the cone type morphology when hexamethylenetetramine
was added in the precursor solution. However, spherical
type ZnO nanoparticles were obtained by incorporating
polyvinyl alcohol during co-precipitation strategy. XRD confirmed
the formation of wurtzite structure in all the samples.
FTIR spectroscopy revealed the presence of ZnO characteristic
peaks. Moreover, 3-D directional growths and the
presence of UV-Vis broadband multi-absorption peaks, and
green to orange photoluminescence emissions confirmed
the potential application of the synthesized ZnO particles in
various piezoelectric and luminescence applications.

- by saad salman
- •
- Chemical Engineering, Materials Science, Chemistry, Crystallography

Polyvinylidene fluoride and its copolymers are a well-known family of low-cost fer- roelectric materials widely used for the fabrication of devices for a wide range of applications. A biocompatibility, high optical quality, chemical and mechanical durability of Poly(vinylidene fluoride– trifluoroethylene), (P(VDF–TrFE)), makes it particularly attractive for designing of effective coating layers for different diagnostic techniques. In present work, the nonlinear optical characterization of P(VDF-TrFE) coating films deposited onto a glass substrate was done. Advantages of the coating application for cells/substrates in the field of multiphoton imaging the efficiency of such coating layer for long-duration characterization of so-called harmonic nanoparticles (HNPs) were shown. It was analyzed the influence of glass surface protection by P(VDF-TrFE) film from an effect of HNPs sticking to the walls of the flow-cell, for effective studying of the optical harmonics generation efficiency of HNPs making the analysis more robust.