Testing of photocatalytic potential of silver nanoparticles produced through nonthermal plasma reduction reaction and stabilized with saccharides

2021 ◽  
pp. 1-14
Author(s):  
N.U.H. Altaf ◽  
M.Y. Naz ◽  
S. Shukrullah ◽  
H.N. Bhatti

In this study, silver nanoparticles (AgNPs) were produced through an atmospheric pressure plasma reduction reaction and tested for photodegradation of methyl blue (MB) under sunlight exposure. The argon plasma born reactive species were used to reduce silver ions to AgNPs in the solution. Glucose, fructose and sucrose were also added in the solution to stabilize the growth process. The glucose stabilized reaction produced the smallest nanoparticles of 12 nm, while sucrose stabilized reaction produced relatively larger nanoparticles (14 nm). The nanoparticles exhibited rough morphology and narrow diameter distribution regardless of stabilizer type. The narrow diameter distribution and small band gap helped activating majority of nanoparticles at a single wavelength of light spectrum. The band gap energy of AgNPs varied from 2.22 eV to 2.41 eV, depending on the saccharide type. The photoluminescence spectroscopy of AgNPs produced emission peaks at 413 nm, 415 nm, and 418 nm. The photocatalytic potential of AgNP samples was checked by degrading MB dye under sunlight. The degradation reaction reached a saturation level of 98% after 60 min of light exposure.

2019 ◽  
Vol 31 (12) ◽  
pp. 2804-2810
Author(s):  
Anti Kolonial Prodjosantoso ◽  
Oktanio Sigit Prawoko ◽  
Maximus Pranjoto Utomo ◽  
Lis Permana Sari

In this article, the synthesis of silver nanoparticles through a reduction reaction process using Salacca zalacca extract is reported. The AgNPs were characterized using X-ray diffraction, transmission electron microscopy, Fourier transform infrared and UV-visible spectrophotometry methods. The AgNPs antibacterial activity was determined against of Gram-positive bacteria (Staphylococcus epidermidis) and Gram-negative bacteria (Escherichia coli). The main functional groups contained in Salacca zalacca extract are carbonyl, hydroxyl and nitrile groups, which are believed to reduce the silver ions to metal. The surface plasmon resonance values of brownish red AgNPs are in the range of 410 nm to 460 nm. The structure of AgNPs is face centered cubic (FCC). The diameter of silver nanoparticles crystallite is 14.2 ± 2.6 nm. The AgNPs growth inhibition zones of Escherichia coli and Staphylococcus epidermidis are 9.6 mm and 9.2 mm, respectively.


2015 ◽  
Vol 1113 ◽  
pp. 560-565 ◽  
Author(s):  
Nor Ain Ramli ◽  
Junaidah Jai ◽  
Noorsuhana Mohd Yusof ◽  
Norashikin Ahmad Zamanhuri

In this research, green synthesis of silver nanoparticles using elaeis guineensis leaves extract was investigated and the influence of pH and reaction time in the reaction kinetic were studied. UV-visible spectrophotometer was used to monitor the reduction reaction of silver ions to silver nanoparticles and formation of silver nanoparticles shown at sharp peak at pH 10 with λmax of 391 nm. Transmission electron microscopy (TEM) shows silver nanoparticles are polydispersed and irregular shape with size ranging from 55-85 nm. Formation of silver nanoparticles was confirmed by energy dispersive x-ray analysis (EDAX) and crystalline structure using XRD. From this research, it was found that pH 10 influenced the reaction kinetic therefore reduce the reaction time.


2014 ◽  
Vol 575 ◽  
pp. 36-40 ◽  
Author(s):  
Nor Ain Ramli ◽  
Junaidah Jai ◽  
Noorsuhana Mohd Yusof

In this research, green synthesis of silver nanoparticles using elaeis guineensis leaves extract was investigated and the effect of reaction time in reduction mechanism and particle size is studied. UV-visible sprectrophotometer was used to monitored the reduction reaction of silver ions to silver nanoparticles and formation of silver nanoparticles shown at 15 minutes. Transmission electron microscopy (TEM) and field emission scanning electron microcopy (FESEM) shows polydispersed and irregular shape of silver nanoparticles with aggregation. Further confirms the formation of silver nanoparticles by energy dispersive x-ray analysis (EDAX). From this research, it was found that the increasing reaction time increases the rate of reduction reaction of silver ions.


Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5444
Author(s):  
Lukasz Marciniak ◽  
Martyna Nowak ◽  
Anna Trojanowska ◽  
Bartosz Tylkowski ◽  
Renata Jastrzab

In colloidal methods, the morphology of nanoparticles (size and shape) as well as their stability can be controlled by changing the concentration of the substrate, stabilizer, adding inorganic salts, changing the reducer/substrate molar ratio, and changing the pH and reaction time. The synthesis of silver nanoparticles was carried out according to the modified Lee and Meisel method in a wide pH range (from 2.0 to 11.0) using citric acid and malic acid, without adding any additives or stabilizers. Keeping the same reaction conditions as the concentration of acid and silver ions, temperature, and heating time, it was possible to determine the relationship between the reaction pH, the type of acid, and the size of the silver nanoparticles formed. Obtained colloids were analyzed by UV-Vis spectroscopy and investigated by means of Transmission Electron Microscope (TEM). The study showed that the colloids reduced with citric acid and malic acid are stable over time for a minimum of seven weeks. We observed that reactions occurred for citric acid from pH 6.0 to 11.0 and for malic acid from pH 7.0 to 11.0. The average size of the quasi-spherical nanoparticles changed with pH due to the increase of reaction rate.


2021 ◽  
Vol 4 (1) ◽  
pp. 237-242
Author(s):  
Н. D. Dudok ◽  
◽  
N. B. Semenyuk ◽  
T. V. Skorokhoda ◽  
Yu. Ya. Melnyk ◽  
...  

The influence of technological factors on the regularities of obtaining silver nanoparticles using polyvinylpyrrolidone as reducing agent has been researched and its influence in compositions content on antimicrobial properties of last ones have been defined. The impact of temperature and polyvinylpyrrolidone content as well as Ag+ concentration on the kinetics of the reduction reaction of silver ions was determined. Silver-containing composites in the form of porous blocks and films were synthesized and their bactericidal and fungicidal properties were studied. The possibility of practical application of composites in biomedical area in the processes of osteogenesis has been confirmed.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6082
Author(s):  
Noor Ul Huda Altaf ◽  
Muhammad Yasin Naz ◽  
Shazia Shukrullah ◽  
Abdul Ghaffar ◽  
Muhammad Irfan ◽  
...  

Pure TiO2 nanoparticles (TiO2NPs) were produced via the sol–gel method and then coated with silver nanoparticles (AgNPs) to reduce their optical band gap. The concurrent synthesis and immobilization of AgNPs over TiO2NPs was achieved through the interaction of an open-air argon plasma jet with a solution of silver nitrate/stabilizer/TiO2NPs. The one-pot plasma synthesis and coating of AgNPs over TiO2NPs is a more straightforward and environmentally friendly method than others. The plasma-produced Ag/TiO2 nanocomposites were characterized and tested for their photocatalytic potential by degrading different concentrations of methyl blue (MB) in water. The dye concentration, oxidant dose, catalyst dose, and reaction time were also optimized for MB degradation. XRD results revealed the formation of pure AgNPs, pure TiO2NPs, and Ag/TiO2 nanocomposites with an average grain size of 12.36 nm, 18.09 nm, and 15.66 nm, respectively. The immobilization of AgNPs over TiO2NPs was also checked by producing SEM and TEM images. The band gap of AgNPs, TiO2NPs, and Ag/TiO2 nanoparticles was measured about 2.58 eV, 3.36 eV, and 2.86 eV, respectively. The ultraviolet (UV) results of the nanocomposites were supportive of the degradation of synthetic dyes in the visible light spectrum. The AgNPs in the composite not only lowered the band gap but also obstructed the electron–hole recombinations. The Ag/TiO2 composite catalyst showed 90.9% degradation efficiency with a 5 ppm dye concentration after 120 min of light exposure.


Author(s):  
Vidyasagar G M ◽  
Shankaravva B ◽  
R Begum ◽  
Imrose ◽  
Sagar R ◽  
...  

Microorganisms like fungi, actinomycetes and bacteria are considered nanofactories and are helpful in the production of nanoparticles useful in the welfare of human beings. In the present study, we investigated the production of silver nanoparticles from Streptomyces species JF714876. Extracellular synthesis of silver nanoparticles by Streptomyces species was carried out using two different media. Silver nanoparticles were examined using UV-visible, IR and atomic force microscopy. The size of silver nanoparticles was in the range of 80-100 nm. Antimicrobial activity of silver nanoparticle against bacteria such as E. coli, S. aureus, and dermatophytes like T. rubrum and T. tonsurans was determined. Thus, this study suggests that the Streptomyces sp. JF741876 can produce silver ions that can be used as an antimicrobial substance.


2021 ◽  
Vol 359 ◽  
pp. 129859
Author(s):  
Li Wang ◽  
Govindasami Periyasami ◽  
Ali Aldalbahi ◽  
Vincenzo Fogliano

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