scholarly journals Enhanced Photocatalytic and Antibacterial Performance of ZnO Nanoparticles Prepared by an Efficient Thermolysis Method

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 608 ◽  
Author(s):  
Md. Hanif ◽  
Insup Lee ◽  
Jeasmin Akter ◽  
Md. Islam ◽  
Ali Zahid ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Zno Nanoparticles ◽  
Zinc Acetate Dihydrate ◽  
Hexagonal Wurtzite Structure ◽  
Thermal Method ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
E Coli ◽  
Antibacterial Performance ◽  
Short Time

ZnO nanoparticles (ZnO-NPs) were synthesized by a straightforward modified thermal method using only one chemical: zinc acetate dihydrate. The process is environmentally safer than other methods because it does not involve other chemicals or a catalyst, acid, or base source. X-ray diffraction analysis indicated that the ZnO-NPs crystallize in the hexagonal wurtzite structure. The UV–vis absorption spectra revealed a marked redshift, which is critical for enhanced photocatalytic activity. We used methylene blue for photocatalytic activity tests and found an excellent degradation percentage (99.7%) within a short time (80 min). The antibacterial activity of the synthesized ZnO-NPs was tested against Escherichia coli at different concentrations of ZnO-NPs. The analysis revealed that the minimum inhibitory concentration (MIC) of the ZnO-NPs against E. coli was 30–50 μg/mL. Our ZnO-NPs were found to be more effective than previously reported ZnO-NPs synthesized via other methods.

scholarly journals Photocatalytic Properties of Microwave-Synthesized TiO2 and ZnO Nanoparticles Using Malachite Green Dye

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
A. K. Singh ◽  
Umesh T. Nakate
Keyword(s):  
Malachite Green ◽  
Zno Nanoparticles ◽  
Uv Light ◽  
Hexagonal Wurtzite Structure ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Malachite Green Dye ◽  
Photodegradation Rate ◽  
Scherrer Formula

TiO2 and ZnO nanoparticles (NPs) were synthesized using microwave-assisted method. Synthesized NPs were characterized for their structure, morphology, and elemental composition using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The crystallite size of synthesized NPs of TiO2 and ZnO was about 12.3 and 18.7 nm as obtained from the Scherrer formula from the most intense XRD peak. The synthesized NPs have been found to be in stoichiometric ratio having anatase and hexagonal wurtzite structure for TiO2 and ZnO, respectively, and are spherical in shape. Surface area of TiO2 and ZnO NPs was found to be about 43.52 m2/g and 7.7 m2/g. Photocatalytic (PC) properties of synthesized NPs were studied for malachite green (MG) dye under UV light. TiO2 NPs were found to be highly photocatalytically active among the two, having efficiency and apparent photodegradation rate of 49.35% and , respectively.

Synthesis and Characterization Silver, Zinc Oxide and Hybrid Silver/Zinc Oxide Nanoparticles for Antimicrobial Applications

Nano LIFE ◽  
2014 ◽  
Vol 04 (01) ◽  
pp. 1440003 ◽  
Author(s):  
Myisha Roberson ◽  
Vijaya Rangari ◽  
Shaik Jeelani ◽  
Temesgen Samuel ◽  
Clayton Yates
Keyword(s):  
Zinc Oxide ◽  
Zno Nanoparticles ◽  
Biomedical Application ◽  
Fungal Growth ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
E Coli ◽  
Transmission Electron ◽  
20 Nm

Silver ( Ag ) and zinc oxide ( ZnO ) are well known for both antimicrobial and pro-healing properties. Here, we present a novel method to synthesize Ag and ZnO nanoparticles (NPs), as well as hybrid Ag / ZnO NPs using a custom, temperature controlled microwave assisted technique. Microwave synthesis has been shown not only to enhance the rate of chemical reactions, but also in some cases to give higher product yields over thermal heating. The as-synthesized NPs were characterized by X-ray diffraction (XRD) to study the crystalline structure, composition and purity. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) was used to study particle size, shape, composition and morphology. These results indicated that the as-prepared Ag NPs are spherical in shape and ~ 20 nm in sizes. The ZnO NPs are typically rod shaped and the particle sizes are ~ 20 nm in width and 100 nm in length. These NPs were tested for antibacterial and/or antifungal properties using disc diffusion assays. Results show microwave synthesized NPs inhibit growth of S. aureus, E. coli and C. albicans at 50 μ g/mL treatment concentration. Ag NPs were most effective in inhibiting bacterial and fungal growth at the concentrations tested followed by hybrid Ag / ZnO and ZnO nanoparticles. These results also suggest that the hybridization of ZnO to Ag NPs may reduce the toxicity of Ag NPs. Further studies are needed to understand the functional interaction between the two types of NPs and to improve their ability for biological or biomedical application.

scholarly journals Enhancement of the Photocatalytic Activity of ZnO Nanoparticles and the Relationship With Thermal Annealing Temperature

2021 ◽  
Author(s):  
F.H. Aragon
Keyword(s):  
Photocatalytic Activity ◽  
Thermal Annealing ◽  
Zno Nanoparticles ◽  
Annealing Temperature ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Zno Nanopowder ◽  
Vis Spectroscopy ◽  
Mean Size

Abstract The present study describes the synthesis, characterization, and photocatalytic activity (PCA) evaluation of ZnO nanoparticles (NPs) prepared via the polymeric precursor method in a first step, following annealing in the range of 500 to 900 oC in a second step. The formation of the wurtzite crystal structure is confirmed via x-ray diffraction data analysis. Thermal annealing treatments in atmospheric air are carried out to control the crystallite mean size and physical properties. The UV-Vis spectroscopy measurements show a decreasing trend of the optical band gap of the as-fabricated ZnO NPs, from ~3.4 eV to ~3.1 eV, as the annealing temperature increases. The PCA of the ZnO NPs against methylene blue dye revealed an increase in efficiency as the annealing temperature increases, reaching with a maximum performance for the sample annealed at ~700 °C. Our findings suggest that the PCA of the ZnO NPs does not show a straightforward dependence on the NPs’ size, but it seems to be correlated with the density of defects, such as oxygen vacancies, which are modulated by the annealing temperature. In addition, thermoluminescence glow curves exhibit a well-defined peak located at ~622 K for the as-prepared ZnO nanopowder. The peak intensity shows a decreasing trend with the annealing temperature up to ~700 °C. This result is correlated with the modulation of traps as the annealing temperature increases, which seems to be directly related to the amount of trapped charges (electrons and holes), leading to a marked reduction of the PCA.

Simplistic Synthesis and Enhanced Photocatalytic Performance of Spherical ZnO Nanoparticles Prepared from Arabinose Solution

2019 ◽  
Vol 74 (10) ◽  
pp. 937-944 ◽  
Author(s):  
Babiker Y. Abdulkhair ◽  
Mutaz E. Salih ◽  
Nuha Y. Elamin ◽  
A. MA. Fatima ◽  
A. Modwi
Keyword(s):  
Zno Nanoparticles ◽  
Photocatalytic Performance ◽  
Hexagonal Wurtzite Structure ◽  
Zinc Nitrate ◽  
Wurtzite Structure ◽  
Sugar Solution ◽  
X Ray Diffraction ◽  
Pollutant Degradation ◽  
X Ray ◽  
Good Crystallinity

AbstractStrenuous efforts have been employed to prepare zinc oxide (ZnO) with eco-friendly methods; however, few studies have reported the fabrication of ZnO using a sustainable procedure. In this study, spherical ZnO nanoparticles were successfully fabricated for photocatalysis applications using a simple and eco-friendly method using an arabinose sugar solution. The ZnO nanoparticles with a wurtzite structure were obtained by combining zinc nitrate and arabinose in water, followed by heating, evaporation, and calcinations at different annealing temperatures. The annealed ZnO photocatalysts were characterised via X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The findings revealed a hexagonal wurtzite structure and good crystallinity with crystallite size increasing from 18 to 31 nm by means of an increase in the annealing temperature. The photocatalytic performance was examined to determine the degradation of mix dye waste. The spherical ZnO nanoparticles showed mix pollutant degradation of 84 % in 25 min at 400 °C.

scholarly journals Antibacterial and Photocatalytic Properties of ZnO Nanoparticles Obtained from Chemical versus Saponaria officinalis Extract-Mediated Synthesis

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2072
Author(s):  
Maria Antonia Tănase ◽  
Maria Marinescu ◽  
Petruta Oancea ◽  
Adina Răducan ◽  
Catalin Ionut Mihaescu ◽  
...  
Keyword(s):  
Microwave Irradiation ◽  
Zno Nanoparticles ◽  
Model Compound ◽  
Size Composition ◽  
Inorganic Nanoparticles ◽  
Bacterial Strains ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Reaction Conditions ◽  
Saponaria Officinalis

In the present work, the properties of ZnO nanoparticles obtained using an eco-friendly synthesis (biomediated methods in microwave irradiation) were studied. Saponaria officinalis extracts were used as both reducing and capping agents in the green nanochemistry synthesis of ZnO. Inorganic zinc oxide nanopowders were successfully prepared by a modified hydrothermal method and plant extract-mediated method. The influence of microwave irradiation was studied in both cases. The size, composition, crystallinity and morphology of inorganic nanoparticles (NPs) were investigated using dynamic light scattering (DLS), powder X-ray diffraction (XRD), SEM-EDX microscopy. Tunings of the nanochemistry reaction conditions (Zn precursor, structuring agent), ZnO NPs with various shapes were obtained, from quasi-spherical to flower-like. The optical properties and photocatalytic activity (degradation of methylene blue as model compound) were also investigated. ZnO nanopowders’ antibacterial activity was tested against Gram-positive and Gram-negative bacterial strains to evidence the influence of the vegetal extract-mediated synthesis on the biological activity.

scholarly journals Synthesis, characteristics, and photocatalytic activity of zinc oxide nanoparticles stabilized on the stone surface for degradation of metronidazole from aqueous solution

2021 ◽  
Vol 8 (1) ◽  
pp. 55-63
Author(s):  
Amir Nasser Alibeigi ◽  
Neda Javid ◽  
Majid Amiri Gharaghani ◽  
Zhila Honarmandrad ◽  
Fatemeh Parsaie
Keyword(s):  
Zinc Oxide ◽  
Removal Efficiency ◽  
Zno Nanoparticles ◽  
Advanced Oxidation Process ◽  
Degradation Kinetics ◽  
Hexagonal Wurtzite Structure ◽  
Sem Analysis ◽  
Thermal Method ◽  
Average Crystalline Size ◽  
Stone Surface

Background: The presence of antibiotics such as metronidazole in wastewater even at low concentrations requires searching for a suitable process such as advanced oxidation process (AOP) to reduce the level of pollutants to a standard level in water. Methods: In this study, zinc oxide (ZnO) nanoparticles were synthesized by thermal method using zinc sulfate (ZnSO4 ) as a precursor, then, stabilized on stone and was used as a catalyst, in order to degrade metronidazole by photocalytic process. Effective factors on the removal efficiency of metronidazole including the initial metronidazole concentration, contact time, pH, and 0.9 gL-1 ZnO stabilized on the stone surface were investigated. Results: The X-ray diffraction (XRD) studies showed that the synthesized nanomaterials have hexagonal Wurtzite structure. Also, scanning electron microscopy (SEM) analysis revealed that the average crystalline size of the synthesized ZnO particles was in the range of 1.9-3.2 nm. The spectra represented a sharp absorption edge at 390 nm for ZnO nanoparticles corresponding to band gap of 3.168 eV. The BET-BJH specific surface area of the synthesized ZnO nanoparticles was 25.504 m2 /g. The EDS spectrum of ZnO nanoparticles showed four peaks, which were identified as Zn and O. The maximum removal efficiency was 98.36% for the synthetic solution under a specific condition (pH = 11, reaction time = 90 minutes, ZnO concentration = 0.9 gL-1, and the initial concentration of metronidazole = 10 mgL-1). The photocatalytic degradation was found to follow pseudo-first-order degradation kinetics. Conclusion: Therefore, the ZnO nanoparticles synthesized by thermal decomposition are suitable and effective photocatalytic materials for degradation of pharmaceutical contaminants.

scholarly journals Synthesis of ZnO nanoparticles by a hybrid electrochemical-thermal method: influence of calcination temperature

2015 ◽  
Vol 50 (1) ◽  
pp. 21-28 ◽  
Author(s):  
F Hassan ◽  
MS Miran ◽  
HA Simol ◽  
MAB H Susan ◽  
MYA Mollah
Keyword(s):  
Calcination Temperature ◽  
Zno Nanoparticles ◽  
Zinc Salt ◽  
Thermal Method ◽  
Gravimetric Analysis ◽  
Zno Nps ◽  
X Ray ◽  
Calcination Temperatures ◽  
Ft Ir ◽  
Uv Visible

ZnO nanoparticles (NPs) with size less than 100 nm were successfully prepared by a hybrid electrochemical-thermal method using metallic zinc and NaHCO3 without the use of any zinc salt, template or surfactant. The NPs were characterized by Fourier transform infra-red (FT-IR) spectroscopy, UV-visible spectroscopy, photoluminescence spectroscopy (PL), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy. UV-visible spectral analysis indicated that the particle size increased with increasing calcination temperature. The band gap (3.91-3.83 eV) was higher for synthesized ZnO NPs than their bulk counterparts (3.37 eV). The FT-IR spectra at different calcination temperatures showed the characteristic band for ZnO at 450 cm-1 to be prominent with increasing temperature due to the conversion of precursor into ZnO. The wurtzite hexagonal phase was confirmed by XRD analyses for ZnO NPs calcined at 700oC. The green photoluminescent emission from ZnO NPs at different calcination temperatures is considered to be originated from the oxygen vacancy or interstitial related defects in ZnO. SEM images clearly showed that the NPs are granular and of almost uniform size when calcined at higher temperatures. EDX spectra further confirmed the elemental composition and purity of ZnO obtained on calcination at 700oC. The NPs are well dispersed near or above calcination temperature of 700oC.Bangladesh J. Sci. Ind. Res. 50(1), 21-28, 2015

Silver-Supporting Diatomite Preparation and Antibacterial Performance Test

2011 ◽  
Vol 694 ◽  
pp. 742-745 ◽  
Author(s):  
Fen E Hu ◽  
Zhi Juan Wang ◽  
Jun Li Li
Keyword(s):  
Performance Test ◽  
Silver Content ◽  
Antimicrobial Effect ◽  
X Ray Diffraction ◽  
E Coli ◽  
Agno3 Solution ◽  
Antibacterial Performance ◽  
Reaction Solution ◽  
Vacuum Heating ◽  
Dipping Time

The silver-supporting diatomite was prepared by the vacuum heating decomposition method with diatomite as the carrier and AgNO3 solution as the reaction solution. Its structure was characterized by X-ray diffraction (XRD). The factors influencing silver content of diatomite have been discussed in prepared silver-supporting diatomite. The results show that when the mass ratio of diatomite to AgNO3 is 10:1, the dipping time of 2 hours and the decomposing temperature of 350°C are suitable to preparing silver-supporting diatomite. XRD analyses show that the Ag loaded on the surface and micropore of the diatomite is nano-silver. The antimicrobial effect of silver-supporting diatomite was investigated against Escherichia coli (E. coli). The results show that the silver-supporting diatomite have obvious inhibiting effect on E. coli and its minimum inhibitory concentration decrease with increase of its silver content. The silver-supporting diatomite with the silver content of 1.46% is suitable to kill E. coli in water.

Characteristics and Photocatalytic Activity of Sm Doped ZnO Nanoparticles

2019 ◽  
Vol 799 ◽  
pp. 179-184 ◽  
Author(s):  
Pavels Rodionovs ◽  
Dzidra Jankovica ◽  
Jānis Grabis
Keyword(s):  
Photocatalytic Activity ◽  
Calcination Temperature ◽  
Zno Nanoparticles ◽  
Sol Gel ◽  
Spherical Shape ◽  
Order Rate Constant ◽  
X Ray Diffraction ◽  
First Order ◽  
Microwave Assisted ◽  
Gel Combustion

Sm2O3/ZnO nanoparticles were prepared via microwave-assisted hydrothermal and sol-gel combustion synthesis. Characteristics of obtained samples were compared in dependence of Sm2O3 content and calcination temperature. Prepared nanostructures were characterized with scanning electron microscopy and X-ray diffraction. Nanoparticles prepared via microwave-assisted hydrothermal and sol-gel method have flower-like and spherical shape respectively. The photocatalytic activity of samples under solar light simulated illumination was found to be affected by content of Sm2O3, calcination temperature and preparation method. The first-order rate constant of MB solution degradation of samples prepared via microwave-assisted hydrothermal method approximately three times exceeds that of sol-gel samples.

scholarly journals Antibacterial Activity of Ag-Doped TiO2 and Ag-Doped ZnO Nanoparticles

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Gebretinsae Yeabyo Nigussie ◽  
Gebrekidan Mebrahtu Tesfamariam ◽  
Berhanu Menasbo Tegegne ◽  
Yemane Araya Weldemichel ◽  
Tesfakiros Woldu Gebreab ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Zno Nanoparticles ◽  
Pathogenic Bacteria ◽  
Anatase Phase ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Sem Images ◽  
X Ray ◽  
Doped Zno

We report in this paper antibacterial activity of Ag-doped TiO2 and Ag-doped ZnO nanoparticles (NPs) under visible light irradiation synthesized by using a sol-gel method. Structural, morphological, and basic optical properties of these samples were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectrum, and UV-Vis reflectance. Room temperature X-ray diffraction analysis revealed that Ag-doped TiO2 has both rutile and anatase phases, but TiO2 NPs only have the anatase phase. In both ZnO and Ag-doped ZnO NPs, the hexagonal wurtzite structure was observed. The morphologies of TiO2 and ZnO were influenced by doping with Ag, as shown from the SEM images. EDX confirms that the samples are composed of Zn, Ti, Ag, and O elements. UV-Vis reflectance results show decreased band gap energy of Ag-doped TiO2 and Ag-doped ZnO NPs in comparison to that of TiO2 and ZnO. Pathogenic bacteria, such as Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, were used to assess the antibacterial activity of the synthesized materials. The reduction in the viability of all the three bacteria to zero using Ag-doped ZnO occurred at 60 μg/mL of culture, while Ag-doped TiO2 showed zero viability at 80 μg/mL. Doping of Ag on ZnO and TiO2 plays a vital role in the increased antibacterial activity performance.

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