Formation Of Zinc Oxide Nanoparticles Research Articles

<i>Catharanthus roseus</i>-Mediated Zinc Oxide Nanoparticles against Photocatalytic Application of Phenol Red under UV@365 nm

Catharanthus roseus leaf extract has potential efficien-cy for the formation of biosynthesized zinc oxide (ZnO) nanoparticles against dye degradation with various time intervals. The leaves of C. roseus were utilized as reducing agent for the formation of metal precursors into metal oxide nanoparticles. C. roseus -mediated ZnO nanoparticles were confirmed by vari-ous analytical techniques such as UV-Vis, FT-IR, XRD and morphological studies by SEM and TEM. Results show that green synthesized ZnO nanoparti-cles are directly proportional to reaction time. The phytoconstituents present in leaf extract of C. roseus play a major role in ZnO nanoparticles formation by acting as a reducing agent.

Vegetable Peel Waste for the Production of ZnO Nanoparticles and its Toxicological Efficiency, Antifungal, Hemolytic, and Antibacterial Activities.

Zinc oxide (ZnO) nanoparticles (NPs) are important materials when making different products like sun screens, textiles, and paints. In the current study, the photocatalytic effect of prepared ZnO NPs from Moringa oleifera (M. oleifera) was evaluated on degradation of crystal violet (CV) dye, which is largely released from textile industries and is harmful to the environment. Preliminarily, ZnO NP formation was confirmed using a double beam ultraviolet visible (UV-Vis) spectrophotometer; further, the NP size was estimated using XRD analysis and the functional group analysis was determined using Fourier transform infrared (FT-IR) spectroscopy. The morphology of the synthesized NPs was found to be a hexagonal shape using SEM and TEM analysis and elemental screening was analyzed using EDX. ZnO NPs were shown sized 40–45 nm and spherical in shape. The degradation percentage of ZnO NPs was calculated as 94% at 70 min and the rate of the reaction –k = 0.0282. The synthesized ZnO NPs were determined for effectiveness on biological activities such as antifungal, hemolytic, and antibacterial activity. ZnO NPs showed good antifungal activity against Alternaria saloni and Sclerrotium rolfii strains. Further, we have determined the hemolytic and antibacterial activity of ZnO NPs and we got successive results in antibacterial and hemolytic activities.

Study the Effect of Liquid Layer Level on the Formation of Zinc Oxide Nanoparticles Synthesized by Liquid-Phase Pulsed Laser Ablation

This work is focused on studying the effect of liquid layer level (height above a target material) on zinc oxide nanoparticles (ZnO and ZnO2) production using liquid-phase pulsed laser ablation (LP-PLA) technique. A plate of Zn metal inside different heights of an aqueous environment of cetyl trimethyl ammonium bromide (CTAB) with molarity (10-3 M) was irradiated with femtosecond pulses. The effect of liquid layer height on the optical properties and structure of ZnO was studied and characterized through UV-visible absorption test at three peaks at 213 nm, 216 nm and 218 nm for three liquid heights 4, 6 and 8 mm respectively. The obtained results of UV–visible spectra test show a blue shift accompanied with decreasing the liquid level above the target due to the increase in ablation rate and particles production. This blue shift indicates getting a smaller size of nanoparticles and the quantum confinement property of nanoparticles. Also the FTIR transmittance spectra of ZnO2 nanoparticles prepared in these states show a characteristic ZnO absorption at 435 cm−1 – 445 cm−1.

Green mediated synthesis of zinc oxide nanoparticles for the photocatalytic degradation of Rose Bengal dye

Zinc oxide (ZnO) nanoparticles were synthesised by a simple method using leaf extract of jackfruit (Artocarpus heterophyllus). The phytochemicals present in the leaf act as stabilising agents. The green synthesised ZnO nanoparticles were characterized by X-ray diffraction (PXRD), Scanning Electron microscopy (FESEM), Energy dispersive spectroscopy (EDS) and Transmission electron microscopy (TEM). XRD pattern confirmed the formation of crystalline ZnO nanoparticles. The SEM images showed porous, sponge-like agglomerated structures. TEM analysis showed the ZnO nanoparticles formed to have hexagonal wurtzite structure and the particles ranging between 15 and 25nm. The green synthesised ZnO nanoparticles exhibited excellent photodegradation efficiency (>80%, 0.24g/L, 1h) against Rose Bengal dye, a main water-pollutant released by the textile industries. The characterisation results confirmed that the ZnO nanoparticles can be efficiently synthesised using jackfruit leaf extract as stabiliser and the photodegradation results proved the efficiency of the green synthesised ZnO nanoparticles for the degradation of Rose Bengal dye.

Fabrication of nanostructured ZnO thin films based NO2 gas sensor via SILAR technique

Zinc oxide (ZnO) thin films have been widely used as an effective gas sensor element. In the present study, nanostructured thin films of ZnO were prepared by using the simplistic and economical successive ion layer adsorption and reaction (SILAR) technique. The effects of SILAR cycles on the structural, optical, surface morphological and electrical properties of nanostructured ZnO thin films were investigated. Characterization techniques such as XRD, UV-vis, PL, FESEM, and Hall measurement were utilized to study the physical and chemical properties of the synthesized films. XRD confirms the formation of hexagonal phase structural ZnO thin films. FE-SEM analysis reveals the formation of well-dispersed ZnO nanoparticles having sizes of ∼18–40nm. The SILAR cycles play a key role in the synthesis of nanostructured ZnO thin films and it is found that, with increasing SILAR cycles, the grain size continues increasing. Optical studies confirm the presence of oxygen vacancies in synthesized ZnO thin films. Finally, the ZnO thin films were exposed to NO2 gas with a concentration of 100ppb–200ppm and the resulting resistance transient was recorded. The nanostructured ZnO thin films synthesized at 30 SILAR cycles displays an enhancement of gas sensing performance and exhibit significantly higher responses (∼5%per ppm). Moreover, our ZnO thin-film-based gas sensor is sensitive to very low concentrations of dangerous NO2 (100ppb). The sensitive gas sensor used to trace level NO2 detection, synthesized via simple SILAR route proves the novelty of our work. The present report provides a new direction in fabricating nanostructured ZnO thin films for low-cost and efficient gas sensing applications.

Efficient Photodegradation of Organics in Acidic Solution by ZnO–Smectite Hybrids

Zinc oxide has been immobilized in layered clay minerals (natural montmorillonite and synthetic saponite) by ion exchange and simultaneous oxidation. The products exhibit blueshifted absorption bands (onsets at 346 and 374 nm for the montmorillonite and saponite systems, respectively) compared with that of bulk zinc oxide (393 nm), thereby showing the formation of zinc oxide nanoparticles. The samples are characterized by the broad photoluminescence centered at 545 nm for zinc oxide in montmorillonite and the relatively sharp and strong photoluminescence observed at 436 nm for zinc oxide in saponite. The photocatalytic activities of the ZnO–smectite hybrids towards the decomposition of an aqueous solution of Methylene Blue were examined and revealed that both catalysts function even in acidic solution, which is an advantage of nanoparticles (ZnO in the present case) supported on smectites.

Limonia acidissima L. leaf mediated synthesis of zinc oxide nanoparticles: A potent tool against Mycobacterium tuberculosis

Objective/backgroundThe present investigation was undertaken to synthesize zinc oxide nanoparticles using Limonia acidissima L. and to test their efficacy against the growth of Mycobacterium tuberculosis. MethodsThe formation of zinc oxide nanoparticles was confirmed with UV–visible spectrophotometry. Fourier transform infrared spectroscopy shows the presence of bio-molecules involved in the stabilization of zinc oxide nanoparticles. The shape and size was confirmed with atomic force microscope, X-ray diffraction, and high resolution transmission electron microscope. These nanoparticles were tested for their effect on the growth of M. tuberculosis through the microplate alamar blue assay technique. ResultsThe UV–visible data reveal that an absorbance peak at 374nm confirms formation of zinc oxide nanoparticles and they are spherical in shape with sizes between 12nm and 53nm. These nanoparticles control the growth of M. tuberculosis at 12.5μg/mL. ConclusionPhytosynthesis of zinc oxide nanoparticles is a green, eco-friendly technology because it is inexpensive and pollution free. In the present investigation, based on our results we conclude that the aqueous extract of leaves of L. acidissima can be used for the synthesis of zinc oxide nanoparticles. These nanoparticles control the growth of M. tuberculosis and this was confirmed with the microplate alamar blue method. The potential of biogenic zinc oxide nanoparticles may be harnessed as a novel medicine ingredient to combat tuberculosis disease.

Interaction of Chitosan/Zinc Oxide Nanocomposites and their Antibacterial Activities with Escherichia coli

Zinc Oxide nanoparticles (ZNPs) and CS/Zinc oxide nanocomposites (CS/ZnO NCs) were successfully synthesized by wet chemical method. Formation of ZNPs and the interaction of CS/ZnO NCs were characterized by X-ray diffraction (XRD), Zeta potential, and Transmission Electron Microscopy (TEM) techniques. Thermal stability of the prepared samples was characterized by Thermogravimetric Analysis (TGA). TEM images shows the interaction between the ZNPs and CS polymer and the particles has spherical like structure with average crystallite size of 22 nm and is in good agreement with XRD results. The aim of this study was to investigate the attachment of these nanoparticles with Escherichia coli (E. coli) bacterial outermost cell membrane and their mode of action against these bacterial strains by agar well diffusion method and resazurin dye reduction method. Both the test materials synthesized revealed resistivity against E. coli up to 6 mg/mL.

Biosynthesis of Zinc Oxide Nanoparticles Using Ixora Coccinea Leaf Extract—A Green Approach

Green synthesis of metal oxide nanoparticles using plant extract is a promising alternative to traditional method of chemical synthesis. In this paper, we report the synthesis of nanostructured zinc oxide particles by biological method. Highly stable and spherical zinc oxide nanoparticles are produced by using zinc acetate and Ixora coccinea leaf extract. Formation of zinc oxide nanoparticles has been confirmed by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Dynamic light scattering analysis (DLS), zetapotential study and Scanning Electron Microscope with the Energy Dispersive X-ray studies (EDX). Dynamic light scattering analysis shows average particle size of 145.1 nm whereas high zeta potential value confirms the stability of formed zinc oxide nanoparticles. The Scanning Electron Microscope reveals spherical morphology of nanoparticles and Energy Dispersive X-ray analysis confirms the formation of highly pure zinc oxide nanoparticles. The zinc oxide nanoparticles from Ixora coccinea leaves are expected to have applications in biomedical, cosmetic industries, biotechnology, sensors, medical, catalysis, optical device, coatings, drug delivery and water remediation, and also may be applied for electronic and magneto-electric devices. This new eco-friendly approach of synthesis is a novel, cheap, and convenient technique suitable for large scale commercial production.

Linkers and coordinated solvent molecules; the two effective factors on formation of zinc oxide nanoparticles from metal–organic frameworks

The host and the apohost frameworks of Zn2(ndc)2(DMF)2∙(H2O)4 (1∙DMF∙H2O) and Zn2(bdc)2(H2O)2∙(DMF)2 (2·H2O·DMF), (H2ndc=2,6-naphthalene dicarboxylic acid, H2bdc=benzene-1,4-dicarboxylic acid and DMF=N,N-Dimethylformamide), were synthesized, characterized and subsequently used for preparing of ZnO nanoparticles. The morphology of initial precursors has direct influence on agglomeration tendency of resulting ZnO nanoparticles. Linkers and coordinated solvent molecules are the two effective factors on the formation of zinc oxide nanoparticles from these metal–organic frameworks.

Synthesis of zinc oxide nanoparticles using tea leaf extract and its application for solar cell

We report the synthesis of zinc oxide (ZnO) nanoparticles and its composite with natural graphite (NG) powder for application in solar cell. ZnO nanoparticles were synthesized using green tea leaf extract as non-toxic and eco-friendly reducing material under microwave irradiation. The formation of ZnO nanoparticles was monitored by the colour changes during the reaction. The synthesized ZnO nanoparticles were characterized by particle size analyzer (dynamic light scattering), scanning electron microscope, UV–visible spectroscopy, atomic force microscope and fluorescence spectroscopy. The average particle size of the ZnO nanoparticles was found to be 26 nm. The synthesized ZnO nanoparticles were further used to prepare ZnO/NG composite material with commercially available NG powder. The current–voltage (I–V) characteristics of thin film of ZnO/NG nanocomposite were investigated. J SC (short-circuit photocurrent), V OC (open-circuit photovoltage), FF (fill factor) and η (efficiency of the solar cell) were measured for ZnO/NG nanocomposite. Interestingly, the cell showed a good power conversion efficiency of 3.54% with high stability.

Microwave assisted synthesis and characterisation of a zinc oxide/tobacco mosaic virus hybrid material. An active hybrid semiconductor in a field-effect transistor device

Tobacco mosaic virus (TMV) has been employed as a robust functional template for the fabrication of a TMV/zinc oxide field effect transistor (FET). A microwave based approach, under mild conditions was employed to synthesize stable zinc oxide (ZnO) nanoparticles, employing a molecular precursor. Insightful studies of the decomposition of the precursor were done using NMR spectroscopy and material characterization of the hybrid material derived from the decomposition was achieved using dynamic light scattering (DLS), transmission electron microscopy (TEM), grazing incidence X-ray diffractometry (GI-XRD) and atomic force microscopy (AFM). TEM and DLS data confirm the formation of crystalline ZnO nanoparticles tethered on top of the virus template. GI-XRD investigations exhibit an orientated nature of the deposited ZnO film along the c-axis. FET devices fabricated using the zinc oxide mineralized virus template material demonstrates an operational transistor performance which was achieved without any high-temperature post-processing steps. Moreover, a further improvement in FET performance was observed by adjusting an optimal layer thickness of the deposited ZnO on top of the TMV. Such a bio-inorganic nanocomposite semiconductor material accessible using a mild and straightforward microwave processing technique could open up new future avenues within the field of bio-electronics.

Formation of zinc oxide particles in cetyltrimethylammonium-smectites

Zinc oxide was prepared in the interlayer space of cetyltrimethylammonium-smectites (a natural montmorillonite and a synthetic saponite) by the reaction between the aqueous solutions of zinc chloride and sodium hydroxide in the presence of cetyltrimethylammonium-smectites. The products were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, as well as scanning electron, transmission electron, and optical microscopies. The formation of zinc oxide nanoparticles in the interlayer space of cetyltrimethylammonium-smectites was indicated by the transmission electron micrograph, diffuse reflectance absorption and the photoluminescence spectra. The photoluminescence of zinc oxide was affected by the interactions with cetyltrimethylammonium cation and silicate layer. The photoluminescence intensities of zinc oxide in cetyltrimethylammonium-saponite were higher than those in cetyltrimethylammonium-montmorillonite due to the quenching impurity in montmorillonite. Thus, the luminescence characteristics (both intensity and the energy) were controlled by the host–guest interactions with selection of host and modification.

Biosynthesis and characterization of phyto mediated zinc oxide nanoparticles: A green chemistry approach

In this study, we describe synthesis and characterization of zinc oxide nanoparticles from aquatic weed by a green chemistry approach. The aim of this work is to synthesize zinc oxide nanoparticles from Eichhornia crassipes leaf extract by low cost technology as against the other available technique and eco-friendly method. Aqueous leaf extract acts as a reducing and capping agent in during synthesis of nanoparticles. Formation of zinc oxide nanoparticles, optical properties, size and morphology has been analyzed by UV–vis spectrophotometer, XRD, SEM with EDX and TEM. SEM and TEM analysis show that zinc oxide nanoparticles were spherical shape and average particles size in 32±4nm. Biological method for synthesis of zinc oxide nanoparticles using plant extracts has been suggested as a possible eco-friendly alternative to chemical and physical methods.

Study of silicon implanted with zinc and oxygen ions via Rutherford backscattering spectroscopy

The structural features and dopant profiles of a Si surface layer implanted with Zn+ and O+ ions are studied via Rutherford backscattering spectroscopy based on the analysis of He2+-ion spectra with the use of the channeling technique. The doping-impurity redistribution is analyzed upon the formation of zinc-oxide nanoparticles. The sample surface morphology is examined by means of atomic-force microscopy and scanning electron microscopy under secondary-electron emission conditions. X-ray phase analysis of the implanted layers is carried out.

Thermal annealing-induced formation of ZnO nanoparticles: Minimum strain and stress ameliorate preferred c-axis orientation and crystal-growth properties

Nanocrystalline zinc oxide (ZnO) thin films have been deposited on glass substrates using a sonicated sol–gel dip-coating technique at various thermal annealing (Ta) temperatures. The Ta temperature was varied to range from 300 to 600°C in intervals of 50°C in an open atmosphere. To obtain desirable piezoelectric properties, the correlations between Ta and the characteristics of ZnO thin films (crystallisation, optical and electrical behaviour) were investigated. The as-deposited films have large compressive stresses of 0.49GPa, which relaxed to 0.27GPa as the Ta temperature increased to 500°C. Optical parameters, such as optical transmittance, absorption coefficient and energy band gap, have been studied and discussed with respect to Ta. All films exhibit a transmittance above 50% in the visible region. It was found that the compressive stresses in the films cause a decrease in the optical band gap, whereas the tensile stress reveals an incline pattern with the optical band gap. This result corroborated with the crystallinity along the c-axis plane. The highest crystallinity value was achieved at the lowest stress value. An identical trend was observed for the resistivity values from the I–V measurement. Moreover, an increase in the crystallite size from 10 to 39nm as the level of Ta increased was noticed. The thickness of the films also decreased when Ta increased, and denser films were obtained as a result. A qualified ZnO thin film with good piezoelectric properties has been prepared using a sonicated sol–gel dip-coating technique with various Ta. Experimental results show that Ta has the greatest influence on the final properties of the ZnO thin films.

Green Synthesis of Zinc Oxide Nanoparticles

Nephelium lappaceum L. peels was effectively used for the synthesis of zinc oxide nanoparticles as a natural ligation agent. The role of rambutan extrac on the formation of zinc oxide nanoparticles was confirmed employing HPLC and GC-MS studies. The XRD and TEM revealed the crystallinity and spherical morphology of the biosynthesized nanoparticles. The size of the particles was found to be 20 nm as deduced from XRD and TEM analysis.

Synthesis, characterisation and gas sensing application of nano ZnO material

Zinc oxide (ZnO) nanomaterial was synthesised by hydrothermal method. The formation of ZnO nanoparticles were confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED) and UV studies. XRD analysis confirmed the powder to be ZnO with wurtzite structure, with crystallite size ranging from 5 to 25 nm. Observation from TEM images confirmed that the grains were nearly hexagonal rod type in nature with sizes from 22 to 56 nm. The thick films of nano ZnO were prepared by screen-printing technique in desired pattern. The surface morphology of the films was studied by scanning electron microscopy (SEM). The gas sensing performance of the materials have been investigated for various interfering gases such as CO, Cl2, NH3 and H2S etc at operating temperature varying from 50°C to 400°C. The results indicate that the nano ZnO material thick film showed much better gas response than the usual ZnO materials to H2S gas (100ppm) at 250°C. The nanoshaped hexagonal rod would improve the sensitivity and selectivity of the sensors. The selectivity, response and recovery time of the sensor were measured and presented. ZnO nanomaterial is excellent potential candidates for gas sensors.

The Influence of Calcination Temperature on the Formation of Zinc Oxide Nanoparticles by Thermal-Treatment

Zinc oxide nanoparticles were synthesized by the thermal-treatment method. Polyvinyl pyrrolidone was used as capping agent and Zinc nitrate was used as a precursor. The samples were calcined at 500 and 550°C for removal of the organic compounds. The structural characteristics of the calcined samples were examined by X-ray diffraction and transmission electron microscopy. The results show that the average particle size increases with increase in calcination temperature. The optical properties were characterized at room temperature using a UV–Vis spectrophotometer in the wavelength range between 200–800 nm and the band gap energy was calculated from reflectance spectra using kubalka munk function and the results indicated that the band gap energy decreased from 3.23 eV at 500 oC to 3.21 eV at 600 °C due to an increase of particle size. This simple thermal-treatment method has advantages of the pure nanoparticles formation as no additional chemicals were required, a lack of by-product effluents, and environmentally friendly process.

Zinc oxide nanoparticles loaded active packaging, a challenge study against Salmonella typhimurium and Staphylococcus aureus in ready-to-eat poultry meat

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.