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In this study, silver nanoparticles (AgNPs) were decorated onto functionalized carbon nanotubes (Ag/f-MWCNTs) using a green method under sunlight conditions. The as-synthesized composite was characterized by UV–vis spectroscopy, XRD, FTIR, SEM, and TEM microscopy. In Ag/f-MWCNTs composite, synthesized NPs were spherically shaped, with particle size ranging from 17.1 to 30.5 nm. The photocatalytic degradation activity of Ag/f-MWCNTs composite was evaluated for the degradation of the cationic methylene blue (MB) dye solution. The rate constants for photocatalytic dye degradation were 0.012 and 0.051 min−1 for f-MWCNT and Ag/f-MWCNTs respectively. Compared with that of f-MWCNTs, Ag/f-MWCNTs composite showed high dye degradation activity after irradiation for 60 min. In addition, photocatalytic bacterial inhibition was studied for the gram-negative bacterium Escherichia coli at different time intervals under visible light irradiation. Ag/f-MWCNTs exhibited maximum photocatalytic bacteria inactivation after 120 min. Based on the obtained results, Ag/f-MWCNTs are a tremendously efficient photocatalyst for the degradation of toxic dyes and bacteria inactivation, and the synthesized material serves as an efficient component for wastewater treatment. [ABSTRACT FROM AUTHOR]

A straightforward and environmentally benign method for the synthesis of silver nanoparticles (AgNPs) is reported in this paper. A sustainable and nontoxic polysaccharide carboxy methyl cellulose (CMC) was used as both reducing agent and stabilizer in the process of synthesizing AgNPs. By varying the precursor concentration, solution pH value, reaction temperature and duration, the highly stable and smaller sized AgNPs with narrow size distribution were obtained. The as-synthesized AgNPs were characterized using UV-Vis absorption spectroscopy, high resolution transmission electron microscopy, X-ray diffraction and zeta potential and size analyzer. Measurements of optical spectra showed that the surface plasmon resonance was localized around 404 nm. The TEM images showed that the particles are well dispersed and spherical in shape with an average particle diameter of 11.64 ± 2.32 nm which is less than the value (13.12 ± 1.54 nm) measured by dynamic light scattering. The zeta potential value of AgNPs was measured to be − 62.8 mV which indicated that CMC coated on the surface of as-synthesized AgNPs resulting in the negatively charged surface and the stable in nature. The prepared silver nanoparticles are effective in inhibiting the growth of both gram positive Staphylococcus aureus and gram negative Escherichia coli. [ABSTRACT FROM AUTHOR]

The green synthesis of silver nanoparticles (AgNPs) has been proposed as a simple, eco-friendly and cost effective alternative to chemical and physical methods. The Rhus chinensis plant is one of the well studied medicinal plant and its galls find excellent clinical and therapeutic applications. The present study reports the use of water extract from galls of R. chinensis as a reducing agent and formation of AgNPs from silver nitrate solution by a green synthesis route. The AgNPs formation was observed visually by color change and the absorbance peak at 450 nm was observed by UV-Visible spectrophotometer. The shape, size, and morphology of synthesized AgNPs were monitored by transmission electron microscopy and field-emission scanning electron microscopy. The face centered cubic structure of AgNPs was confirmed by X-ray diffraction pattern and element composition by energy dispersive X-ray analysis. The Fourier transform infrared spectroscopy spectrum revealed that the presence of components acts as a reducing and capping agent. The antibacterial activity was performed using the agar well diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration were determined by broth dilution and spread plate method respectively. Synthesized nanoparticles were spotted as triangular and hexagonal shape and the particle size was around 150 nm. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (Ag-NPs) have been synthesized using extract of Chelidonium majus root in aqueous solution at room temperature. The root extract was able to reduce Ag to Ag and stabilized the nanoparticles Different physico-chemical techniques including UV-Vis spectroscopy, transmission electron microscopy and powder X-ray diffraction (PXRD) were used for the characterization of the biosynthesized Ag-NPs obtained. The surface plasmon resonance band appeared at 431 nm is an evidence for formation of Ag-NPs. TEM imaging revealed that the synthesized Ag-NPs have an average diameter of around 15 nm and with spherical shape. Moreover the crystalline structure of synthesized nanoparticles was confirmed using XRD pattern. Furthermore antimicrobial activities of synthesized Ag-NPs were evaluated against Escherichia coli -ATCC 25922 and Pseudomonas aeruginosa ATCC 2785 bacteria strain. [ABSTRACT FROM AUTHOR]