scholarly journals UV-Light Mediated Biosynthesis of Silver Nanowires; Characterization, Dye Degradation Potential and Kinetic Studies

2021 ◽  
Vol 13 (23) ◽  
pp. 13220
Author(s):  
Faisal Ali ◽  
Zahid Ali ◽  
Umer Younas ◽  
Awais Ahmad ◽  
Ghulam Mooin-ud-din ◽  
...  

Herrin, a simple and eco-friendly method for the synthesis of silver nanowires (Ag-NWs) has been reported. Silver nanowires were synthesized using Psidium guajava seed extract that acted as a reducing agent as well as a stabilizing agent for silver nitrate solution. Synthesis was carried out at 50 °C temperature under continuous UV-irradiation. Silver nanowires were initially characterized by a UV-visible and FTIR spectrophotometer. In addition, morphology and particle size of synthesized Ag-NWs were determined using Field Emission Scanning Electron Microscopy and X-ray diffraction (XRD) techniques. Nanowires were found to have 12.8 μm length and 200–500 nm diameter and cubic phase morphology. Furthermore, the catalytic potential of Ag-NWs for the degradation of methyl orange dye (MO) was determined. The selected dye was degraded successfully that confirmed the catalytic potential of Ag-NWs. The authors concluded that Ag-NWs can be synthesized using plant extract having excellent morphological features as well as impressive catalytic potential.

2021 ◽  
Author(s):  
Faisal Ali ◽  
Zahid Ali ◽  
Ghulam Mooinuddin ◽  
Umer Younas ◽  
Muhammad Parvaiz ◽  
...  

Abstract In the present study, a simple and eco-friendly method for the synthesis of silver nanowires (Ag-NWs) has been reported. Psidium guajava seed extract was used as a reducing agent for silver nitrate solution at 70 °C temperature under continues UV-irradiation, for the production of Ag-NWs. Silver nanowires were initially characterized by using UV-visible and FTIR spectrophotometer. Synthesis of nanowires and involvement of functional groups was confirmed by FT-IR spectra. The morphology and particle size of synthesized Ag-NWs was determined using Field Emission Scanning Electron Microscopy (FESEM) and X-ray diffraction (XRD). XRD results revealed cubic phase morphology of Ag-NWs. Nanowires were found having 12-8 μm length and 300-500 nm diameter. In addition, catalytic potential of the sample for degradation of methyl orange dye (MO) was tracked spectrophotometrically. The results exposed that; bio-synthesized silver nanowires were found having excellent morphological features as well as impressive catalytic potential.


2007 ◽  
Vol 334-335 ◽  
pp. 685-688
Author(s):  
Dong Lin Zhao ◽  
Xia Li ◽  
Wei Dong Chi ◽  
Zeng Min Shen

The filling of multi-walled carbon nanotubes (MWNTs) with metallic silver nanowires via wet chemistry method was investigated. The carbon nanotubes were filled with long continuous silver nanowires. The carbon nanotubes were almost opened and cut after being treated with concentrated nitric acid. Silver nitrate solution filled carbon nanotubes by capillarity. Carbon nanotubes were filled with silver nanowires after calcinations by hydrogen. The diameters of silver nanowires were in the range of 20-40nm, and lengths of 100nm-10μm. We studied the micromorphology of the silver nanowires filled in carbon nanotubes by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Based on the experimental results, a formation mechanism of the Ag nanowire-filled carbon nanotubes was proposed. And the microwave permittivity of the carbon nanotubes filled with metallic silver nanowires was measured in the frequency range from 2 GHz to 18 GHz. The loss tangent of the carbon nanotubes filled with metallic silver nanowires is high. So the carbon nanotubes filled with metallic silver nanowires would be a good candidate for microwave absorbent.


Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1150
Author(s):  
Muhammad Hamza ◽  
Ataf Ali Altaf ◽  
Samia Kausar ◽  
Shahzad Murtaza ◽  
Nasir Rasool ◽  
...  

Dye removal through photocatalytic degradation employing nanomaterials as catalysts is a growing research area. In current studies, photocatalytic alizarin red (AR) dye degradation has been investigated by designing a series of Cr based manganese oxide nanomaterials (MH1–MH5). Synthesized nanomaterials were characterized by powder X-ray diffraction, scanning electron microscopy/energy dispersive x-ray, Brunauer–Emmett–Teller, and photoluminescence techniques and were utilized for photocatalytic AR dye degradation under UV light. AR dye degradation was monitored by UV–visible spectroscopy and percent degradation was studied for the effect of time, catalyst dose, different dye concentrations, and different pH values of dye solution. All the catalysts have shown more than 80% dye degradation exhibiting good catalytic efficiencies for dye removal. The catalytic pathway was analyzed by applying the kinetic model. A pseudo second-order model was found the best fitted kinetic model indicating a chemically-rate controlled mechanism. Values of constant R2 for all the factors studied were close to unity depicting a good correlation between experimental data.


2021 ◽  
Author(s):  
Saravanan M. ◽  
Vigneshwar S. ◽  
Gautham B. Jegadeesan ◽  
Ponnusami Venkatachalam

Abstract Nano-CeO2 was synthesized via the chemical precipitation of cerium precursor solution, and then mixed with nano-ZnO at various weight ratios to obtain ZnO-CeO2nanocomposites. The composites were characterized for their morphological and photocatalytic properties. X-ray diffraction patterns of the pristine metal oxides corresponded well with (1 0 1) and (1 1 1) peaks of hexagonal wurtzite like-ZnO and cubic-phase CeO2, respectively. The band gap of the ZnO-CeO2nanocomposite was 3.08 eV, while that of pristine CeO2 and ZnO powder was 3.24 eV and 3.12 eV respectively. Photocatalytic activity of ZnO-CeO2composite was evaluated at various Reactive Black (RB) dye and catalyst concentrations. A 1:1 wt ratio ZnO-CeO2 nanocompsite provided the maximum (~ 85%) RB oxidation under UV light within 90 minutes. Rate of dye degradation obtained with ZnO-CeO2nanocomposite was almost 1.5 times more than that obtained with bare ZnO. It was observed that increase in CeO2 to ZnO ratio increased oxidation rates up to 1:1 wt ratio. Increasing CeO2 ratio beyond 1:1 wt. ratio did not significantly increase RB oxidation. The results confirm that addition of CeO2 to ZnO has resulted in lowering its bandgap energy and in-turn favors oxidation of RB dye under UV light.


2019 ◽  
Vol 31 (5) ◽  
pp. 1128-1132
Author(s):  
P.P. Badoni ◽  
Goutam Kumar ◽  
Mahender Singh ◽  
Navneet Singh ◽  
Arun K. Khajuria ◽  
...  

In present study, the Geranium wallichianum leaf extract (aqueous) and 1 mM silver nitrate solution (aqueous) were amalgamated to synthesize silver particles within the nanometer range. Initial colour changes and surface-plasmon-resonance (SPR) absorbance band observed in UV-visible spectroscopic study gave support to configuration of silver nano-particles. Silver nanoparticles were characterized by XRD, TEM and FTIR spectroscopy. Then antimicrobial (antibacterial and antifungal) activities of silver nanoparticles against selected microbial strains were studied by well diffusion method. During this work, silver SPR absorption bands between 405-425 nm range were shown by Geranium wallichianum leaf extract mediated synthesized silver nanoparticles sample solutions at different intervals. X-ray diffraction pattern displayed the formation of face centred cubic phase silver nano-structures. TEM measurements confirmed that silver nanoparticles are spherically shaped and maximum particles in 9-16 nm size range having average diameter 12.5 nm. Important FT-IR peaks at 3314.11, 1710.60, 1587.11 and 1347.77 cm-1 were predicted for hydroxyl, carbonyls, unsaturated C-C bonds and phenolic groups respectively. Further from antimicrobial results, it has been found that values of diameter of zone of inhibition (mm) of synthesized silver nanoparticles against B. subtilis, S. aureus, L. plantarum, P. aeruginosa, A. niger and C. albicans strains were 32, 28, 25, 25 35 and not active, respectively. MIC-MLC (μL) values were also determined. At last, it can be concluded that antimicrobial agents of 9-16 nm size range and stabilized by polyhydroxy-bioactive-components present in extract, in the form of silver nanoparticles has been productively synthesized.


2006 ◽  
Vol 11-12 ◽  
pp. 587-590
Author(s):  
Xia Li ◽  
Dong Lin Zhao ◽  
Zeng Min Shen

The filling of multi-walled carbon nanotubes with metallic silver nanowires via wet chemistry method was investigated. The carbon nanotubes were filled with long continuous silver nanowires. The carbon nanotubes were almost opened and cut after being treated with concentrated nitric acid. Silver nitrate solution filled carbon nanotubes by capillarity. Carbon nanotubes were filled with silver nanowires after calcinations by hydrogen. The diameters of silver nanowires were in the range of 20-40 nm, and lengths of 100 nm - 10 μm. We studied the micromorphology of the silver nanowires filled in carbon nanotubes by transmission electron microscopy (TEM) and X-ray diffraction (XRD). Based on the experimental results, a formation mechanism of the Ag nanowire-filled carbon nanotubes was proposed.


2020 ◽  
Vol 14 (3) ◽  
pp. 2075-2083
Author(s):  
Sheik Shehensha ◽  
Jyothi M. Vijaya

To prepare and characterize silver nanoparticles from Guava leaves (Psidium guajava), extracts (chloroform and ethanol). The fabricated silver nanoparticles were tested on resistant fungal strains, Aspergillus niger and Candida glabrata. Psidium guajava leaf extracts were obtained by cold maceration method, by using Chloroform and Ethanol. To one mL of extract 2mM silver nitrate solution was added. The mixture was kept overnight in a dark chamber at room temperature. The solution was centrifuged at 10,000 rpm for 15 minutes and filtered by wattman filter paper after centrifugation. Psidium guajava leaf extract based silver nanoparticles were prepared and evaluated for anti-fungal activity by microtitre well plate method on resistant strains Aspergillus niger and Candida glabrata. The silver nanoparticles showed significant activity at 120 µL, Nystatin was used as standard.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 183
Author(s):  
Ghiath Jnido ◽  
Gisela Ohms ◽  
Wolfgang Viöl

In the present work, the solution precursor plasma spray (SPPS) process was used to deposit zinc oxide (ZnO) coatings on wood surfaces using zinc nitrate solution as precursor to improve the hydrophobicity and the color stability of European beech wood under exposure to ultraviolet (UV) light. The surface morphology and topography of the wood samples and the coatings were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The formation of ZnO was detected with the help of X-ray photoelectron spectroscopy (XPS) and by Fourier transform infrared (FTIR) spectroscopy. The FTIR spectra of the coated samples showed the typical Zn–O band at 445 cm−1. According to the XPS analysis, the coatings consist of two different Zn-containing species: ZnO and Zn(OH)2. Variation of the deposition parameters showed that the most significant parameters affecting the microstructure of the coating were the solution concentration, the deposition scan speed, and carrier gas flow rate. The wettability behaviors of the coated wood were evaluated by measuring the water contact angle (WCA). The coatings that completely covered the wood substrates showed hydrophobic behaviors. UV-protection of wood surfaces after an artificial UV light irradiation was evaluated by color measurements and FTIR spectroscopy. The ZnO-coated wood surfaces were more resistant to color change during UV radiation exposure. The total color change decreased up to 60%. Additionally, the FTIR spectra showed that the wood surfaces coated with ZnO had more stability. The carbonyl groups formation and C=C-bonds consumption were significantly lower.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Fei Yuan ◽  
Haixia Ma ◽  
Chumei Yuan ◽  
Chun-Sheng Zhou ◽  
Huai-Ming Hu ◽  
...  

Three new Ln(III)-based metal-organic frameworks (MOFs), having general formula [Ln2(L)2(ox)(H2O)2]n (Ln = Nd (1), Sm (2) and Eu (3)) have been synthesized using multifunctional triazole-carboxylate linker 5-(1H-1,2,4-triazol-1-yl)-1,3-benzenedicarboxylic acid (H2L) and...


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