scholarly journals Visible Light-Assisted Soft-Chemistry Route to Silver Nanomaterials at Room Temperature

2019 ◽  
Vol 807 ◽  
pp. 165-170
Author(s):  
Yi Wu ◽  
Xin Liu ◽  
Zi Huang ◽  
Xiang Fei He ◽  
Xi Yang ◽  
...  

Silver nanoparticles (AgNPs) were synthesizd by a light-assisted liquid phase reduction method with sodium hypophosphite as a reducing agent. DTAB was used to perform as the surfactant. AgNPs were characterized with powder X-ray diffraction (XRD) and scanning electron microscope (SEM). The result showed that the nanoparticles are spherical and cube. The effect of temperature on the morphology and properties of silver nanoparticles was investigated. The ultraviolet-visible (UV-vis) absorption and the fluorescent properties of the as-prepared AgNPs were explored.

2018 ◽  
Vol 34 (6) ◽  
pp. 3088-3094 ◽  
Author(s):  
Abdul Wahid Wahab ◽  
Abdul Karim ◽  
Nursiah La Nafie ◽  
Nurafni Nurafni ◽  
I. Wayan Sutapa

Silver nanoparticles have been synthesized by reduction method using extract of Muntingia calabura L. leaf a bioreductor. The process of silver nanoparticles formation was monitored by UV-Vis method. The results showed that the absorbance values increased according to the increase of reaction time. Maximum absorption of silver nanoparticle was obtained at a wavelength of 41-421 nm. The size of silver nanoparticles was determined using a PSA (Particle Size Analyzer) with a particle size distribution of 97.04 nm. The functional groups compound that contribute in the synthesis was analyzed using Fourier Transform Infrared Spectroscopy (FTIR). Morphology of the silver nanoparticles was observed by an Scanning Electron Microscope instrument and the structure characterization of the compounds were analyzed using X-Ray Diffraction. The glucose nanosensor based on silver nanoparticles have the measurement range of 1 mM - 4 mM with the regretion (R2) is 0,9516, the detection limit of sensor is 3,2595 mM, the sensitivity of sensor is 2,0794 A. mM-1. mM-2.


2017 ◽  
Vol 4 (2) ◽  
pp. 367-372
Author(s):  
Andi Rusnaenah ◽  
Muhammad Zakir ◽  
Prastawa Budi

Biosynthesis of silver nanoparticles (AgNPs) using ketapang leaf extract, modification with p-coumaric acid for detecting melamine has conducted. This research aimed to synthesize AgNPs via bio-reduction method using ketapang leaf extract followed by modification with p-coumaric acid (APK), and evaluating its application detecting melamine. The AgNPs were characterized through ultraviolet-visible absorption spectroscopy (UV-Vis) and X-ray diffraction (XRD). Observation suggested that an increase of incubation time had affected its surface Plasmon resonance trend. Further analysis of crystallite via XRD suggested that nanoparticle size at 43 nm estimated using Debye-Scherer, within the form of unit cells is cubic. The performance of product as melamine detector suggested that the AgNPs-APK had detected melamine in range of concentration from 0.1 to 1000 ppm.


2017 ◽  
Author(s):  
Yusnita Rifai

AbstrakNanopartikel perak telah disintesis menggunakan metode reduksi. Dalam penelitian ini, ekstrak metanol daun Kemangi (Ocimum citriodorum) digunakan sebagai agen pereduksi untuk prekursor AgNO3. Sintesis nanopartikel perak dilakukan dengan mencampurkan laru- tan AgNO3 1mM dengan filtrat ekstrak daun kemangi. Hasil karakterisasi UV-Vis menun- jukkan bahwa nilai absorbansi meningkat dengan meningkatnya waktu kontak reaksi. Pun- cak absorbansi spektrum UV-Vis dari sampel biosintesis nanopartikel perak berkisar pada 427-439 nm selama 1 hari dengan pengadukan dan penyimpanan. Ukuran nanopartikel perak ditentukan menggunakan Pengukur Ukuran Partikel (PSA) dengan rata-rata distribusi uku- ran partikel sebesar 57,38 nm. Efek mekanik dalam proses biosintesis nanopartikel perak cenderung mempercepat pembentukan nanopartikel perak. Hasil karakterisasi menggunakan Difraksi Sinar-X (XRD) diketahui kristalit yang terbentuk memiliki intensitas terbesar pada sudut 38° dengan nilai FWHM 0,66310 (ukuran 0,3 nm) dalam sistem kristal kubik.Kata kunci: Biosintesis, Nanopartikel Perak, Ocimum citriodorum, Karakterisasi AbstractSynthesis of silver nanoparticles by using the reduction method with methanol extract basil (Ocimum citriodorum) leaves, which acted as a reducing agent for AgNO3 precursor have been conducted. Synthesis nanoparticles was carried out by mixing the solution of AgNO3 1mM with filtrate extract of Ocimum leaves. The results of characterization showed that absorbance values increased with the increase in reaction time. Peak of UV-Vis absorption spectrum of biosynthesis sample of silver nanoparticles with stirring and storage each at a wavelength 427-439 nm for 1 day. Silver nanoparticles size was determined by using PSA (Particles Size Analyzer) with an average particle size distribution of 57,38 nm. Mechanical effect in biosynthesis process of silver nanoparticles tends to speed up the formation of silver nanoparticles. The result of characterization by using X-Ray Diffraction (XRD) described that the formed crystal had the angle of 38° with the value of FWHM 0,66310 (sixe 0.3 nm) in cubic crystal system.Key word: Biosynthesis, Silver Nanoparticles, Ocimum citriodorum, Characterization.


2017 ◽  
Vol 727 ◽  
pp. 395-402
Author(s):  
Zi Run Wang ◽  
Xin Liu ◽  
Gui Qi Xie ◽  
Yi Wu ◽  
Ming Nie ◽  
...  

Cu-Ag alloy nanoparticles were synthesized by a liquid phase reduction method. Using sodium formaldehyde sulfoxylate (SFS) as reducing agents, copper-silver bimetallic nanoleaflets with high content of Cu were prepared. The obtained Cu-Ag bimetallic nanocrystal were characterized by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscope (FESEM), high resolution transmission electron microscopy (HRTEM) and transmission electron microscopy (TEM). Different molar ratio of Cu-Ag bimetallic nanomaterials could produce different morphologies. The surfactant β-CD plays a crucial role on the structure of the products. The different molar ratios of Cu-Ag were also investigated. The electrochemical activity was evaluated using cyclic voltammetry (CV), electrochemical hydrogen evolution reaction (HER) in a 0.5M Na2SO4 electrolyte.


2011 ◽  
Vol 197-198 ◽  
pp. 483-486
Author(s):  
Qing Chang Chen ◽  
Wei Guo ◽  
Hang Wu ◽  
Zhen Zhong Zheng ◽  
Ming Zhang ◽  
...  

By the addition of flake Cu particles to polyurethane the infrared emissivity of polymers can be decreased significantly. In this work, the flake copper particles were prepared by solution phase reduction method. The PU pre-polymer was prepared by a typical method which using polyether polyol N220 and tolylene diisocyanate (TDI). Cu/Polyurethane composite was prepared by using incorporation method. The structure and morphology of Cu particles and Cu/Polyurethane composite were characterized by Fourier transform infrared spectrum spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD) and Energy Dispersive X-ray Detector (EDS). Moreover, the effects of copper particles content on infrared emissivity properties of composite were studied too. The results show that the flake Cu particles were prepared and dispersed well in polyurethane matrix. The infrared emissivity of composite was decreased with increasing particles loading. The composites get lowest infrared emissivity 0.546 when the loading of fillers increased to 20%.


Author(s):  
Pengfei Xie ◽  
Wenyuan Ji ◽  
Zhigang Wei

With the progress of science and technology, the research and development of silver nanoparticles has also developed. This paper attempts to prepare a silver nanoparticle by electrolyzing AgNO3 solution with electrochemical reduction method and citric acid as a complexing agent in a certain current and time. The crystal morphology and sample purity of silver nanoparticles were analyzed by X-ray diffractometer. The crystal structure of the nanoparticles was analyzed by scanning electron microscopy (SEM). The crystal structure of the nanoparticles was analyzed by X-ray diffraction. The particle size distribution of the particles was in the range of 125-199 nm, and the carbon paste electrode was modified with the prepared silver nanoparticles. The electrocatalytic activity of the carbon paste electrode was preliminarily explored.


2016 ◽  
Vol 36 (3) ◽  
pp. 287-292 ◽  
Author(s):  
Khakemin Khan ◽  
Ahson Jabbar Shaikh ◽  
Mohammad Siddiq ◽  
Tauqir A. Sherazi ◽  
Mohsan Nawaz

Abstract Copper nanoparticles (CuNPs) are formed inside a microgel assembly by an in situ reduction method, confirmed by changes observed in the absorption spectra of CuNPs at different pH values. The presence of CuNPs has been also confirmed by X-ray diffraction (XRD) studies. The terpolymer microgel p(N-isopropylacrylamide-vinyl acetic acid-acrylamide) (p[NIPAM-VAA-AAm]), which is reported for the first time, was synthesized by free radical emulsion polymerization of a temperature-sensitive NIPAM monomer, pH sensitive VAA monomer and a hydrophilic AAm monomer. The effect of temperature below and above the pKa of VAA and the effect of pH at 20°C in the absence and presence of CuNPs on the hydrodynamic radius of microgel was studied. Size of microgel particles is a function of temperature due to the presence of NIPAM, and a function of pH due to the presence of VAA. The presence of CuNPs has little or no effect on the size of microgels by varying pH, which allows these gels to retain their properties with added benefits of CuNPs for possible drug delivery applications.


2014 ◽  
Vol 900 ◽  
pp. 172-176 ◽  
Author(s):  
Ji Mei Niu ◽  
Zhi Gang Zheng

The Fe3O4 magnetic nanoparticles obtained by the aqueous coprecipitation method are characterized systematically using scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. These magnetic nanoparticles are spheric, dispersive, and have average grain size of 50 nm. The size and magnetic properties of Fe3O4 nanoparticles can be tuned by the reaction temperature. All samples exhibit high saturation magnetization (Ms=53.4 emu·g-1) and superparamagnetic behavior with a block temperature (TB) of 215K. These properties make such Fe3O4 magnetic nanoparticles worthy candidates for the magnetic carriers of targeted-drug or gene therapy in future.


2021 ◽  
Author(s):  
Rahma Rahzelli Zrelli ◽  
Fathia Chehimi-Moumen ◽  
Dalila Ben Hassen-Chehimi ◽  
Malika Trabelsi-Ayadi

Abstract The synthesis of the diphosphate HYP2O7·3H2O was made via soft chemistry route from evaporation of aqueous solution at room temperature. The obtained compound, was characterized by means of X-ray diffraction (XRD) and infrared spectroscopy (IR). The results showed a high purity phase. IR spectrum of this diphosphate revealed usual signals related to P2O7 diphosphate group and water molecules. The thermal decomposition of the synthesized product by DTA / TG proceeded through four stages leading to the formation of the Y2P4O13 as a final product. On the other hand, its decomposition by CRTA took place in three stages leading to the formation of the anhydrous diphosphate HYP2O7 as a final product. X-ray powder diffraction and infrared spectroscopy were used to identify these materials. Furthermore the electrical properties of the HYP2O7 were investigated through impedance complex analysis. Modest conductivity has been observed in this material at relatively medium temperature range. Activation energy of 0.67 and 1.44 eV, was deduced from the corresponding Arrhenius plot.The optical band gap of the title compound is calculated and found to be 2.71 eV.


2021 ◽  
Vol 891 ◽  
pp. 111-115
Author(s):  
Maradhana Agung Marsudi ◽  
Farah Fitria Sari ◽  
Pandu Mauliddin Wicaksono ◽  
Adinda Asmoro ◽  
Arif Basuki ◽  
...  

In this work, silver nanoparticles have been successfully synthesized using simple and environmentally friendly ‘green synthesis’ method using Indonesian wild honey as mediator. Particle count and size can be optimized by varying the silver nitrate precursor and honey concentration, with the help of sodium hydroxide as pH regulator. Based on X-ray diffraction (XRD) result, crystalline structure of Ag has been confirmed in sample with impurities from AgCl. Based on dynamic light scattering (DLS) and transmission electron microscopy (TEM) results, it was found that the smallest average particles size of AgNPs (117.5 nm from DLS and 11.1 nm from TEM) was obtained at sample with 5% w/v of honey and 0.5 mM of AgNO3.


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