Synthesis Of Zinc Oxide Nanoflowers Research Articles

Microwave-assisted synthesis of zinc oxide nanoflowers for improving the rheological and filtration performance of high-temperature water-based drilling fluids

Zinc Oxide (ZnO) nanostructures have proved useful across a wide range of applications like medical technology, electronics, sulfur removal as well as microbial growth control. In the petroleum industry, ZnO nanostructures have been widely researched for application in Drilling Fluids. ZnO has been previously reported to work excellently in enhancing the electrical and thermal properties of water-based drilling fluids (WBDFs). However, the role of morphological features of the nanostructures in influencing the properties of bentonite-laden WBDFs is less understood. In this work, ZnO nanostructures were synthesized under microwave irradiation which resulted in different shapes like rods and flowers. The effect of microwave power and time was observed with Field Emission Scanning Electron Microscopy (FE-SEM) and Dynamic Light Scattering (DLS), and a suitable synthesis criterion was selected for achieving the smallest complex ZnO nanoflowers. These nanoflowers were further characterized for functional group and structural identification. Bentonite/Polymer Nanofluids were prepared and tested for properties like rheology, API, and HPHT filtration before and after thermal aging at 150 °C. The results show ZnO nanoflowers in WBDFs have excellent filtration control ability with ∼56% reduction in HPHT filtrate volume and can impart a flat-line rheological profile. Also, the breaking of nanoflowers into smaller nanorods and some further textural changes is predicted to enhance the stability of the WBDFs due to better dispersion and compact mud cake formation. The study shows that the morphological features of metal oxide nanostructures can be controlled with microwave irradiation and play an effective role in controlling the properties of bentonite/polymer WBDFs.

One-pot greener synthesis of zinc oxide nanoflowers using potato, cauliflower, and pea peel extract with antibacterial application

The greener synthesis of nanoparticles gives alternatives to conventional methods and holds the advantage of cost and economy with controlled toxicity. In this research work, we have reported the synthesis of zinc oxide (ZnO) nanoflowers (NFs) by using aqueous peels extract of Solanum tuberosum (potato), Brassica oleracea (cauliflower), and Pisum sativum (pea). Magnificent colorful NFs of nearly the same size and morphology were developed from all tested bio-extracts. The average particle size of ZnO NFs tailored from cauliflower, potato and pea were 37.91 nm, 42.37 nm, and 28.6 nm, respectively. The maximum absorption peak for NFs was at 390 nm, and the bandgap calculated through the Kubelka-Munk function for ZnO NFs was between 3.28 and 3.29 eV. ZnO NFs were found thermally stable till 200 °C, and 50% mass loss was between 200 and 400 °C. Antimicrobial efficacy of synthesized NFs was evaluated. They were identified as a robust antibacterial agent, and the inhibitory action at 45 µg/mL was figured out as B. subtilis (25.2 mm) > E. coli (24.1 mm) > S. aureus (21.2 mm) > P. aeruginosa (17.3 mm). The results showed that ZnO NFs could be effectively utilized against Gram-positive and Gram-negative bacteria. Nanoflowers were discovered unrivaled for bactericidal action than precursor material against control. Moreover, comparing this work with published articles about greener synthesis of ZnO NPs displays them as more toxic and versatile.

Single-step electrochemical synthesis of zinc oxide nanoflowers and multi-walled carbon nanotubes nanoconjugates

Zinc Oxide (ZnO) nanoparticles are investigated for use in various biomedical applications such as in the treatment of cancer because of their high targeting potential. Zinc oxide nanomaterials when conjugated with multi-walled carbon nanotubes (MWNT) show enhanced properties. In our present work, nano-conjugation between zinc oxide nanoflowers (ZnO NFs) and multi-walled carbon nanotubes has been successfully achieved. Here, we have used a two-electrode electrochemical setup for preparation as well as conjugation between ZnO nanoflowers and MWNT. The x-ray diffraction, Raman spectra, and transmission electron microscopy imaging for the ZnO NFs/MWNT nano-conjugate shows the successful synthesis of the nano-conjugate. The electrochemical method used here is a single step, economical, and without the use of any additional surfactant or capping agents. The only use of pure zinc electrodes as a precursor material favors high purity, easy and a less time-consuming purification process.

Bioinspired synthesis of zinc oxide nano-flowers: A surface enhanced antibacterial and harvesting efficiency

Despite of broad range application, the cost effective, highly stable and reproduceable synthesis of ZnO is needed, especially which can make it biosafe as well. Here, a unique bioinspired synthesis of ZnO nanoflowers (NFs) has been introduced using Withania coagulans extract as reducing agent. Different molar concentrations were assessed to counter the effect of structural, morphological, antibacterial activity and high efficiency of algae harvesting. The UV-spectroscopy authenticates the synthesis of ZnO NFs having Wurtzite hexagonal structure with the size in the range of 360–550 nm. While surface analysis revealed the presence of stabilizing agent like phenolic, amine, etc. on surface of ZnO NFs. These perineum ZnO NFs exhibited a stronger antibacterial with Gram-positive bacteria Staphylococcus aureus as compare to Gram-negative bacteria Pseudomonas aeruginosa and greater harvesting efficiency up to 94% on the account of greater surface area and unique surface chemistry, thus leading a new horizon of more efficient and effective applications for ethanol production.

Green synthesis of zinc oxide nanoflowers using Hypericum triquetrifolium extract: characterization, antibacterial activity and cytotoxicity against lung cancer A549 cells

Zinc oxide nanoparticles have attracted significant interest in recent years due to their unique multifunctional chemical and physical properties along with their biological activities. This study demonstrated for the first time the biogenetic synthesis of zinc oxide nanoparticles by utilization of the methanolic extract of Hypericum triquetrifolium (HT). The obtained nanoparticles (HT‐ZnO) were characterized by ultraviolet–visible spectroscopy (UV–Vis), Fourier‐transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), dynamic light scattering (DLS), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), and transmission electron microscopy (TEM). The shape of the resulted nanoparticles is fusiform nanoflowers with an average hydrodynamic size of 275.46 ± 0.20 nm and a zeta potential of −8.23 ± 0.26 mV. SEM micrographs revealed that HT‐ZnO nanoflowers have a multi‐process structure in which one of the processes is large and the others have similar smaller dimensions. The synthesized nanoflowers have an average length of 312.28 ± 78.93 nm and the tip of its processes has a width of 48.69 ± 9.71 nm. The antimicrobial activity of HT‐ZnO nanoflowers was performed using microbroth dilution format. It showed a bactericidal mode of action against Gram‐positive Staphylococcus aureus and Enterococcus faecalis with MIC/MBC values of 20 μg/mL and 5 μg/mL, respectively. MTT assay had revealed that HT‐ZnO nanoflowers caused a dose‐dependent decline in the viability of A549 adenocarcinomic human alveolar basal epithelial cells with an IC50 value of 20.45 μg/mL. The effect of HT‐ZnO nanoflowers on the migration and colony formation abilities against the same cells was evaluated as well. In conclusion, zinc oxide nanoflowers were successfully synthesized using methanolic extract of H. triquetrifolium. The resulting particles showed a bactericidal effect against Gram‐positiveS. aureus and E. faecalis and a cytotoxic activity against A549 cells.

Synthesis and characterization of ZnO nanoflowers using Chlamydomonas reinhardtii: A green approach

Recently, there has been a lot of interest in the synthesis and application of nanoparticles with anisotropic morphologies. The focus of this study has been to use a biologically mediated, low temperature approach for the synthesis of zinc oxide nanoflowers. “Green” methods have a number of advantages over conventional approaches; these include the use of environmentally benign reactants and its economic feasibility. The cell free extract of Chlamydomonas reinhardtii, a fresh water microalga was used to synthesize the nanoflowers. The nanoflowers were composed of individual nanorods that assembled to form flower‐like structures. The nanorods measured 330 nm in length and these nanorods self‐assembled to form porous nanosheets that were found to measure 55–80 nm. Particle size analysis revealed that the larger porous nanoflowers approximately measured 4 µm. Powder X‐ray diffraction studies revealed that the zinc oxide nanoflowers had a hexagonal wurtzite crystal structure. Fourier transform infrared spectroscopy analysis suggested that algal biomolecules were responsible for the synthesis and stabilization of zinc oxide nanostructures. These nanoflowers demonstrate enhanced photocatalytic activity against methyl orange (MO) under natural sunlight. The effects of dye concentration and catalyst dosage on photocatalysis were also studied. The present approach represents a novel, eco‐friendly method to synthesize zinc oxide nanoflowers that have potential applications in water treatment and dye degradation. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1020–1026, 2016

ZnO nanoflowers: Novel biogenic synthesis and enhanced photocatalytic activity

We demonstrate a novel, unprecedented and eco-friendly mode for the biosynthesis of zinc oxide (ZnO) nanoflowers at ambient room temperature using Bacillus licheniformis MTCC 9555 and assessed their photocatalytic activity. The photocatalytic degradation of methylene blue (MB) dye was analyzed under UV-irradiation. An enhanced photocatalytic activity of ZnO nanoflowers was obtained compared to the earlier reports on ZnO nanostructures and other photocatalytic materials. The mechanism behind the enhanced photocatalytic activity was illustrated with diagrammatic representation. It is assumed that due to larger content of oxygen vacancy ZnO nanoflowers shows enhanced photocatalytic activity. Photostability of ZnO nanoflowers was analyzed for consecutive 3 cycles. The size and morphology of ZnO nanoflowers have been characterized by SEM, TEM and found to be in the size range of 250nm to 1μm with flower like morphology. It was found that ZnO nanoflowers was formed by agglomeration of ZnO nanorods. Further the EDX established the presence of the elemental signal of the Zn and O. XRD spectrum of ZnO nanoflowers confirmed 2θ values analogous to the ZnO nanocrystal. FTIR analysis was carried to determine the probable biomolecules responsible for stabilization of ZnO nanoflowers. The plausible mechanism behind the synthesis of ZnO nanoflowers by Bacillus licheniformis MTCC 9555 was also discussed with diagram representation.

Controlled synthesis of zinc oxide nanoflowers by succinate-assisted hydrothermal route and their morphology-dependent photocatalytic performance

Hierarchical flower-like zinc oxide (ZnO) nanostructures were successfully synthesized by using facile succinate and PEG assisted hydrothermal process. The as-prepared ZnO samples were characterized by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) spectroscopy and UV–visible spectroscopy. The effect of dilution of precursor concentration on the formation of distinctive morphology was systematically studied. The flower-like morphology of ZnO can be effectively tuned by simply varying the precursor concentrations. A plausible growth mechanism for the formation of different hierarchical nanostructures is also proposed. Further, photocatalytic activities of the as-prepared samples were studied by photodegradation of Rhodamine B (RhB).