scholarly journals A Review of the some aspects for the development of ZnO based photocatalysts for a variety of applications

2021 ◽  
Vol 22 (3) ◽  
pp. 585-594
Author(s):  
O.E. Baibara ◽  
M.V. Radchenko ◽  
V.A. Karpyna ◽  
A.I. Ievtushenko
Keyword(s):  
Removal Rate ◽  
High Surface ◽  
High Surface Area ◽  
Antibacterial Properties ◽  
Complex Compounds ◽  
Zinc Oxide Nanostructures ◽  
Band Gap Engineering ◽  
Oxide Nanostructures ◽  
Nanoparticle Surface ◽  
High Removal Rate

Today, one of the most important problems for humanity is the pollution of the environment with various organic compounds that worsen the health of the peoples. The most dangerous pollutants are complex compounds that do not degrade under natural conditions. One way to solve the problem of pollution is to use photocatalysis to degrade harmful compounds. Zinc oxide nanostructures exhibit attractive photocatalytic and antibacterial properties due to the increased reactivity of the nanoparticle surface, which allows the efficient decomposition of organic pollutants. In this review, various methods for enhancing the photoefficiency of ZnO nanostructures are considered. It is shown that ZnO nanoparticles with specific surfaces (spherical, nanowires, nanoflowers), which are characterized by a high surface area, have a high removal rate of various pollutants. Such methods of improving the photocatalytic properties of ZnO as the band gap engineering, doping with metal/nonmetal, the combination of  ZnO with other materials, formation of hybrid structures are considered.

Characterization of Urea versus HMTA in the Preparation of Zinc Oxide Nanostructures by Solution-Immersion Method Grown on Gold-Seeded Silicon Substrate

2011 ◽  
Vol 364 ◽  
pp. 45-49 ◽  
Author(s):  
Azlinda Ab Azlinda ◽  
Zuraida Khusaimi ◽  
Saifollah Abdullah ◽  
Mohamad Rusop
Keyword(s):  
Zinc Oxide ◽  
Silicon Substrate ◽  
High Surface ◽  
High Surface Area ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
Zinc Oxide Nanostructures ◽  
Immersion Method ◽  
Oxide Nanostructures

Zinc oxide (ZnO) nanostructures prepared by immersion method were successfully grown on gold-seeded silicon substrate using Zinc nitrate hexahydrate (Zn (NO3)2.6H2O) as a precursor, separately stabilized with non-toxic urea (CH4N2O) and hexamethylene tetraamine (HMTA). The effect of changing the stabilizer of ZnO solution on the crystal structure, morphology and photoluminescence properties of the resultant ZnO is investigated. X-ray diffraction of the synthesized ZnO shows hexagonal zincite structure. The morphology of the ZnO was characterized using Field Emission Scanning Electron Microscope (FESEM). The growth of ZnO using urea as stabilizer shows clusters of ZnO nanoflower with serrated broad petals were interestingly formed. ZnO in HMTA showed growth of nanorods. The structures has high surface area, is a potential metal oxide nanostructures to be develop for optoelectronic devices and chemical sensors. The formation of ZnO nanostructures is found to be significantly affected by the stabilizer.

scholarly journals Porous ZnO/2–Hydroxyethyl Methacrylate Eluting Coatings for Ureteral Stent Applications

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 376
Author(s):  
Marco Laurenti ◽  
Marta Grochowicz ◽  
Valentina Cauda
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Antibacterial Properties ◽  
Drug Eluting Stent ◽  
Hydroxyethyl Methacrylate ◽  
Swelling Properties ◽  
Future Drug ◽  
Drug Eluting ◽  
Polymer Infiltration

High-surface-area porous coatings represent an interesting option to fabricate eluting stents with additional functionalities, as controlled drug delivery and antibacterial resistance properties. ZnO is a biocompatible material available in various high-surface-area morphologies, with promising antibacterial properties. Hydrophilic 2-hydroxyethyl methacrylate (HEMA) polymers (pHEMA) have been widely investigated for their biomedical applications, thanks to their biocompatibility, absence of toxicity, and tunable swelling properties. This work aims to demonstrate the use of porous ZnO/polymer bilayer coatings for future drug eluting stent applications. Sputtered mesoporous ZnO layers were coated with pHEMA and p(HEMA-co-acrylic acid (AA)) films through vacuum infiltration and drop-casting methods. The last approach was found to be the most suitable one for achieving a good polymer infiltration within the ZnO matrix and to avoid the mechanical detachment of the porous film from the substrate. The corresponding release properties were evaluated by loading a fluorescent dye in the host ZnO matrix, before drop-casting the polymer coating. For pure ZnO, the release of the dye was completed after 2 h. For ZnO/pHEMA, the sustained release of the molecule was achieved with only 30% released after 2 h and 100% released after seven days. In this case, the pH-triggered delivery properties were also demonstrated by switching from neutral to acidic pH conditions. No significant changes were obtained for the ZnO/p(HEMA-co-AA) system, which exhibited a faster swelling behavior and a release profile similar to pure ZnO.

Laser Processing of Silica Aerogels Using Ultrashort Pulses

2000 ◽  
Author(s):  
J. Sun ◽  
J. P. Longtin ◽  
P. M. Norris
Keyword(s):  
Laser Processing ◽  
Material Removal ◽  
Removal Rate ◽  
High Surface ◽  
Laser System ◽  
High Surface Area ◽  
Ultrashort Pulses ◽  
Silica Aerogels ◽  
Ultrafast Laser ◽  
Breakdown Threshold

Abstract Silica aerogels are unique nanostructured materials that possess many distinctive qualities, including extremely low densities and thermal conductivities, very high surface-area-to-volume ratios, and large strength-to-weight ratios. Aerogels, however, are very brittle, and are not readily shaped using traditional machining operations. Ultrafast laser processing may provide an alternative for precision shaping and machining of these materials. This paper discusses investigations of ultrafast laser machining of aerogels for material removal and micromachining. The advantages of ultrafast laser processing include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this work, an amplified femtosecond Ti:sapphire laser system is used to investigate the breakdown threshold, material removal rate, and specific issues associated with laser processing of aerogels, as well as recommendations for further investigations for these unique materials.

A Review on Antibacterial Properties of Biologically Synthesized Zinc Oxide Nanostructures

2020 ◽  
Vol 30 (8) ◽  
pp. 2815-2826 ◽  
Author(s):  
Mohsin Ijaz ◽  
Maria Zafar ◽  
Atif Islam ◽  
Sumera Afsheen ◽  
Tahir Iqbal
Keyword(s):  
Zinc Oxide ◽  
Antibacterial Properties ◽  
Zinc Oxide Nanostructures ◽  
Oxide Nanostructures

Annealing Effect on the Surface Morphology and Photoluminescence Properties of ZnO Nanorod Prepared by Catalytic-Immersion Method Grown on Si and Au/Si Substrate

2013 ◽  
Vol 667 ◽  
pp. 110-114
Author(s):  
Azlinda Ab Aziz ◽  
Zuraida Khusaimi ◽  
Saifollah Abdullah ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Surface Morphology ◽  
Annealing Temperature ◽  
High Surface ◽  
Zno Nanorods ◽  
High Surface Area ◽  
Si Substrate ◽  
Immersion Method ◽  
Oxide Nanostructures ◽  
Hexagonal Shape ◽  
Metal Oxide Nanostructures

ZnO nanorods were prepared by immersion method deposited onto Silicon (Si) and gold-seeded Si (Au/Si) substrate. The annealing temperatures were varied from 400, 500 and 600 °C. The effect of annealing temperature on the surface morphology and photoluminescence characteristics was investigated. The samples were characterized by Field Emission Scanning Electron Microscope (FESEM) to study their morphology and structural properties while the optical properties were characterized at room temperature using Photoluminescence Spectroscope. The shape of ZnO showed growth of nanorods with hexagonal shape. As the annealing temperature increased, the morphology study indicates that particle size of ZnO decreased while the crystallinity increases. The structures has high surface area, is a potential metal oxide nanostructures to be develop for optoelectronic devices and chemical sensors.

Influence of Substrate’s Alignment Strategy to the Growth of ZnO Nano-Petals via Solution-Immersion Method

2012 ◽  
Vol 620 ◽  
pp. 60-65
Author(s):  
Azlinda Ab Aziz ◽  
Zuraida Khusaimi ◽  
Mohamad Rusop
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Immersion Method ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Alignment Strategy

Zinc oxide (ZnO) nanostructures were successfully grown on gold-seeded Si substrate prepared by a solution-immersion method using a novel mixture of an aqueous solution of Zinc nitrate hexahydrate (Zn (NO3)2.6H2O) with a non-toxic, odourless urea (CH4N2O) as a stabilizer. Structural and optical properties of resultant ZnO thin films were investigated by X-Ray Diffraction, FESEM and Photoluminescence Spectroscopy (PL). Clusters of ZnO micro-flower with serrated broad petals with the thickness of petals approximately 60 nm were interestingly formed on the film with horizontal manner of alignment during immersion process. The smallest grain size (29 nm) along (100) orientation was achieve with the alignment of substrate tilt towards 60°. The petals structure has high surface area, is a potential metal oxide nanostructures to be develop for optoelectronic devices and chemical sensors.

scholarly journals Fabrication of Gelatin-ZnO Nanofibers for Antibacterial Applications

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 103
Author(s):  
Nataliya Babayevska ◽  
Łucja Przysiecka ◽  
Grzegorz Nowaczyk ◽  
Marcin Jarek ◽  
Martin Järvekülg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Zno Nanoparticles ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Antibacterial Properties ◽  
Physicochemical Characterization ◽  
Zno Nps ◽  
Electrospinning Technique ◽  
Electron Microscopies

In this study, GNF@ZnO composites (gelatin nanofibers (GNF) with zinc oxide (ZnO) nanoparticles (NPs)) as a novel antibacterial agent were obtained using a wet chemistry approach. The physicochemical characterization of ZnO nanoparticles (NPs) and GNF@ZnO composites, as well as the evaluation of their antibacterial activity toward Gram-positive (Staphyloccocus aureus and Bacillus pumilus) and Gram-negative (Escherichia coli and Pseudomonas fluorescens) bacteria were performed. ZnO NPs were synthesized using a facile sol-gel approach. Gelatin nanofibers (GNF) were obtained by an electrospinning technique. GNF@ZnO composites were obtained by adding previously produced GNF into a Zn2+ methanol solution during ZnO NPs synthesis. Crystal structure, phase, and elemental compositions, morphology, as well as photoluminescent properties of pristine ZnO NPs, pristine GNF, and GNF@ZnO composites were characterized using powder X-ray diffraction (XRD), FTIR analysis, transmission and scanning electron microscopies (TEM/SEM), and photoluminescence spectroscopy. SEM, EDX, as well as FTIR analyses, confirmed the adsorption of ZnO NPs on the GNF surface. The pristine ZnO NPs were highly crystalline and monodispersed with a size of approximately 7 nm and had a high surface area (83 m2/g). The thickness of the pristine gelatin nanofiber was around 1 µm. The antibacterial properties of GNF@ZnO composites were investigated by a disk diffusion assay on agar plates. Results show that both pristine ZnO NPs and their GNF-based composites have the strongest antibacterial properties against Pseudomonas fluorescence and Staphylococcus aureus, with the zone of inhibition above 10 mm. Right behind them is Escherichia coli with slightly less inhibition of bacterial growth. These properties of GNF@ZnO composites suggest their suitability for a range of antimicrobial uses, such as in the food industry or in biomedical applications.

Annealing Effect on the Surface Morphology and Photoluminescence Properties of ZnO Hexagonal Rods by Immersion Method

2012 ◽  
Vol 576 ◽  
pp. 353-356 ◽  
Author(s):  
Ab Aziz Azlinda ◽  
Zuraida Khusaimi ◽  
Fadzilah Suhaimi Husairi ◽  
Nor Iyazi Nasruddin ◽  
S. Abdullah ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Room Temperature ◽  
Annealing Temperature ◽  
High Surface ◽  
High Surface Area ◽  
Photoluminescence Properties ◽  
Immersion Method ◽  
Oxide Nanostructures ◽  
Hexagonal Shape ◽  
Metal Oxide Nanostructures

ZnO hexagonal rod structure were prepared by immersion method deposited onto Si (Si/ZnO) and gold-seeded Si substrate (ZnO/Au/Si). The annealing temperatures were varied from 400, 500 and 600 °C. The effect of annealing temperature on the surface morphology and photoluminescence characteristics was investigated. The samples were characterized by Field Emission Scanning Electron Microscope (FESEM) to study their morphology and structural properties while the optical properties were characterized at room temperature using Photoluminescence Spectroscopy. The shape of ZnO showed growth of rods with hexagonal shape. As the annealing temperature increased, the morphology study indicates that diameter size of ZnO decreased while the crystallinity increases. The structures has high surface area, is a potential metal oxide nanostructures to be develop for optoelectronic devices and chemical sensors.

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