scholarly journals Rapid synthesis and characterization of silver-loaded graphene oxide nanomaterials and their antibacterial applications

2021 ◽  
Vol 8 (2) ◽  
Author(s):  
Jiang Zhu ◽  
Haitao Ni ◽  
Chunyan Hu ◽  
Yuxiang Zhu ◽  
Jinxia Cai ◽  
...  

With the promising potential application of Ag/graphene-based nanomaterials in medicine and engineering materials, the large-scale production has attracted great interest of researchers on the basis of green synthesis. In this study, water-soluble silver/graphene oxide (Ag/GO) nanomaterials were synthesized under ultrasound-assisted conditions. The structural characteristics of Ag/GO were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and energy dispersion spectroscopy, respectively. The results showed the silver particles (AgNPs) obtained by reduction were attached to the surface of GO, and there was a strong interaction between AgNPs and GO. The antibacterial activity was primarily evaluated by the plate method and hole punching method. Antibacterial tests indicated that Ag/GO could inhibit the growth of Gram-negative and Gram-positive bacteria, special for the Staphylococcus aureus .

Author(s):  
Jyoti Singh ◽  
Mahesh S. Bhadane ◽  
Vikas Dubey ◽  
Sanjay Daga Dhole ◽  
Jairam Manam ◽  
...  

The chapter provides useful information about synthesis and characterization of dysprosium doped oxide and fluoride-based phosphors such as SrGd2O4, CaSO4, and CaF2. Various techniques (e.g., acid-recrystallization, chemical co-precipitation, and homogenous precipitation cum auto-combustion methods) were adopted to synthesize these phosphors for large-scale production. All the prepared phosphors were characterized by x-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy techniques. The thermoluminescence (TL) studies were performed after different irradiation sources such as gamma rays, thermal neutrons, and low energy ions (H, Ar, and N), respectively. Linear dose responses were observed in a wide range of doses for all the samples. Various trapping parameters, namely order of kinetics, activation energy, and frequency factors, were calculated by using computerized glow curve deconvolution (CGCD) method.


2018 ◽  
Vol 23 (1) ◽  
Author(s):  
Renata Hack ◽  
Cláudia Hack Gumz Correia ◽  
Ricardo Antônio de Simone Zanon ◽  
Sérgio Henrique Pezzin

ABSTRACT Natural graphite is an inexpensive and abundant source to obtain graphene nanosheets. The most efficient method for large-scale production is the chemical method, which is based on the oxidation of natural graphite. This paper reports the synthesis and characterization of graphene obtained by the Hummers method with some modifications. The results indicate a high degree of graphite oxidation, proving that the process was efficient. Analyses of field emission scanning electron microscopy (FEG), transmission electron microscopy (TEM), Raman spectroscopy, thermogravimetric analysis (TGA) and X-ray diffraction showed that the graphene produced presented characteristics similar to the commercial graphene.


1998 ◽  
Vol 13 (10) ◽  
pp. 2950-2955 ◽  
Author(s):  
Yong Dong Jiang ◽  
Zhong Lin Wang ◽  
Fuli Zhang ◽  
Henry G. Paris ◽  
Christopher J. Summers

A forced hydrolysis technique is used for preparing Y2O3: Eu3+ powders at low processing temperatures. The technique uses yttrium oxide, europium oxide, and nitric acid and urea, and has the potential for large-scale production for industrial applications. Several experimental conditions have been examined to optimize the luminescence efficiency. The best result was found to be at 2 mol% Eu doping and a 2 h firing of 1400 °C. Microstructural information provided by x-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) have been applied to interpret the observed luminescent properties.


Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 279 ◽  
Author(s):  
Talia Tene ◽  
Gabriela Tubon Usca ◽  
Marco Guevara ◽  
Raul Molina ◽  
Francesco Veltri ◽  
...  

The oxidative exfoliation of graphite is a promising approach to the large-scale production of graphene. Conventional oxidation of graphite essentially facilitates the exfoliation process; however, the oxidation procedure releases toxic gases and requires extensive, time-consuming steps of washing and reduction to convert exfoliated graphene oxide (GO) into reduced graphene oxide (rGO). Although toxic gases can be controlled by modifying chemical reactions, filtration, dialysis, and extensive sonication are unfavorable for large-scale production. Here, we report a complete, scalable, and green synthesis of GO, without NaNO3, followed by reduction with citric acid (CA). This approach eliminates the generation of toxic gases, simplifies the washing steps, and reduces the time required to prepare rGO. To validate the proposed method, we present spectroscopical and morphological studies, using energy-dispersive X-ray spectroscopy (EDS), UV-visible spectroscopy, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermal gravimetric analysis (TGA) is used to analyze the thermal properties of GO and rGO. This eco-friendly method proposes a complete guideline protocol toward large-scale production of oxidized graphene, with potential applications in supercapacitors, fuel cells, composites, batteries, and biosensors.


2013 ◽  
Vol 233 ◽  
pp. 297-304 ◽  
Author(s):  
Shichoon Lee ◽  
Sung Hun Eom ◽  
Jin Suk Chung ◽  
Seung Hyun Hur

2018 ◽  
Vol 34 (6) ◽  
pp. 2832-2837 ◽  
Author(s):  
Mohd Zaid Ansari ◽  
Mohammad Nadeem Lone ◽  
Shabana Sajid ◽  
Weqar Ahmad Siddiqui

The present work shows a facile route for the preparation of graphene layers and for the first time Zante currants extract used for the effective deoxygenation of graphene oxide has been reported. Zante currants (ZC) extract reduce effectively GO into few layered structures of graphene (FLG). The morphology of few layers graphene and graphene oxide (GO) were investigated by SEM and TEM. Reduction effect on graphene oxide confirm by other technique like Raman, FTIR, XRD and UV spectrophotometry. This procedure keep away the use of hazardous chemicals, thus providing a new hope for large scale production of chemically reduced graphene.


2014 ◽  
Vol 1004-1005 ◽  
pp. 1013-1016 ◽  
Author(s):  
Chang Yi Kong ◽  
Yuuki Shiratori ◽  
Takeshi Sako ◽  
Futoshi Iwata

A green method to synthesize the reduced graphene oxide using supercritical fluid has been developed, which is an environmentally friendly and efficient route. The reduced graphene oxide has been examined by X-ray diffraction, Raman spectroscopy. We have also studied the effects of reduction temperatures and supercritical fluids on the electrical properties of reduced graphene oxide. It was found that ethanol has higher reducing capability than CO2at all temperatures (200 - 400°C) examined in this study for graphene oxide reduction. As a result, reduced graphene oxide (6300 S/m) from supercritical ethanol treatment has 5 times as high conductivity as that from supercritical CO2treatment at the reduction temperature of 400°C. This green process is applicable for large scale production of reduced graphene oxides for various practical applications.


2014 ◽  
Vol 243 ◽  
pp. 340-346 ◽  
Author(s):  
Ming Zhang ◽  
Bin Gao ◽  
Diana C. Vanegas ◽  
Eric S. McLamore ◽  
June Fang ◽  
...  

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