Green Synthesis of Silver Nanoparticles Using a Terrestrial Weed Mucuna bracteata DC and Their Adsorption Study on Reactive Red 120

2020 ◽  
Vol 12 (2) ◽  
pp. 207-214
Author(s):  
N. Mahalaxmi ◽  
E. V. Ramasamy

An eco-friendly method of silver nanoparticle (SNPs) synthesis is presented by utilizing a terrestrial weed, Mucuna bracteata DC. This plant based nanoparticles are effectively reducing anionic dye, Reactive Red 120 by adsorption—an effective method of dye removal from effluents. The method enables the rapid synthesis of SNPs at ambient conditions without any use of hazardous chemicals. The characterization of nanoparticles with UV-visible spectrophotometer indicated the absorption peak at 299 of blue shift; SEM and TEM analysis has revealed the presence of particles with spherical morphology of about 30–80 nm in size; The X-ray diffraction and EDAX studies confirmed the presence of silver atoms; The FT-IR spectra indicated the role of hydroxyl functional groups and amino group of the phyto extract, are responsible for the reduction and stabilizing silver ions in to SNPs. The dye removal results showed that the adsorption process increases when the concentration of nanoparticles increases. The adsorption process obeys Langmuir isotherm (R2 value were 0.994 and RL value lies between 0 and 1) and pseudo second order kinetics (R2 value were 0.998) more effectively. The isotherm and kinetic model confirmed that Mucuna bracteata based SNPs can be used as a suitable adsorbent for the removal of dyes from effluents.

2020 ◽  
Vol 38 (9-10) ◽  
pp. 483-501
Author(s):  
Nguyen Thi Huong ◽  
Nguyen Ngoc Son ◽  
Vo Hoang Phuong ◽  
Cong Tien Dung ◽  
Pham Thi Mai Huong ◽  
...  

The Fe3O4/Talc nanocomposite was synthesized by the coprecipitation-ultrasonication method. The reaction was carried out under a inert gas environment. The nanoparticles were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), fourier-transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry techniques (VSM), the surface area of the nanoparticles was determined to be 77.92 m2/g by Brunauer-Emmett-Teller method (BET). The kinetic data showed that the adsorption process fitted with the pseudo-second order model. Batch experiments were carried out to determine the adsorption kinetics and mechanisms of Cr(VI) by Fe3O4/Talc nanocomposite. The adsorption process was found to be highly pH-dependent, which made the material selectively adsorb these metals from aqueous solution. The isotherms of adsorption were also studied using Langmuir and Freundlich equations in linear forms. It is found that the Langmuir equation showed better linear correlation with the experimental data than the Freundlich. The thermodynamics of Cr(VI) adsorption onto the Fe3O4/Talc nanocomposite indicated that the adsorption was exothermic. The reusability study has proven that Fe3O4/Talc nanocomposite can be employed as a low-cost and easy to separate.


2021 ◽  
Vol 22 (7) ◽  
pp. 3447
Author(s):  
Sihan Feng ◽  
Xiaoyu Du ◽  
Munkhpurev Bat-Amgalan ◽  
Haixin Zhang ◽  
Naoto Miyamoto ◽  
...  

Chitosan (CS) modified with ethylenediamine tetraacetic acid (EDTA) was further modified with the zeolite imidazole framework (ZIF-8) by in situ growth method and was employed as adsorbent for the removal of rare-earth elements (REEs). The material (EDTA–CS@ZIF-8) and ZIF-8 and CS were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and nitrogen adsorption/desorption experiments (N2- Brunauer–Emmet–Teller (BET)). The effects of adsorbent dosage, temperature, the pH of the aqueous solution, contact time on the adsorption of REEs (La(III), Eu(III), and Yb(III)) by EDTA–CS@ZIF-8 were studied. Typical adsorption isotherms (Langmuir, Freundlich, and Dubinin–Radushkevich (D-R)) were determined for the adsorption process, and the maximal adsorption capacity was estimated as 256.4 mg g−1 for La(III), 270.3 mg g−1 for Eu(III), and 294.1 mg g−1 for Yb(III). The adsorption kinetics results were consistent with the pseudo-second-order equation, indicating that the adsorption process was mainly chemical adsorption. The influence of competing ions on REE adsorption was also investigated. After multiple cycles of adsorption/desorption behavior, EDTA–CS@ZIF-8 still maintained high adsorption capacity for REEs. As a result, EDTA–CS@ZIF-8 possessed good adsorption properties such as stability and reusability, which have potential application in wastewater treatment.


2021 ◽  
Vol 11 (6) ◽  
pp. 14986-14997

In this study, the adsorption of Congo red dye in an aqueous solution on two synthetic clay adsorbents, MgAl-LDH (2:1) and MgAl-LDH (3:1), was investigated using batch system experiments. The adsorbents' characterization was carried out by various techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy FT-IR. The conditions applied in the adsorption experiments including the mass of adsorbent, initial concentration, contact time, pH, and temperature. The kinetic data were modeled by pseudo-first-order and pseudo-second-order. Langmuir and Freundlich's models analyzed the adsorption isotherms of Congo red on the two adsorbents. It was found that the adsorption process could be described by Langmuir isotherm. The maximum amount of adsorption is 285.71 and 166.66 mg/g for MgAl-LDH (2:1) and MgAl-LDH (3:1), respectively. Thermodynamic parameters such as enthalpy ∆H°, enthalpy ∆S°, and free enthalpy ∆G° were also evaluated to predict the nature of adsorption.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohamed S. Yahia ◽  
Ahmed S. Elzaref ◽  
Magdy B. Awad ◽  
Ahmed M. Tony ◽  
Ahmed S. Elfeky

Abstract Commercial Granulated Active Carbon (GAC) has been modified using 10 Gy dose Gamma irradiation (GAC10 Gy) for increasing its ability of air purification. Both, the raw and treated samples were applied for removing Chlorpyrifos pesticide (CPF) from ambient midair. Physicochemical properties of the two materials were characterized by Fourier Transform Infrared (FT-IR) and Raman spectroscopy. The phase formation and microstructure were monitored using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), supported with Energy-Dispersive X-ray (EDX). The Surface area measurement was detected using BET particle size prosometry. Obtained outcomes showed that, the maximum adsorption capacity, given by Langmuir equations, was greatly increased from 172.712 to 272.480 mg/g for GAC and GAC10 Gy, respectively, with high selectivity. The overall removal efficiency of GAC10 Gy was notably comparable to that of the original GAC-sorbent. The present study indicated that, gamma irradiation could be a promising technique for treating GAC and turned it more active in eliminating the pesticides pollutants from surrounding air. The data of equilibrium has been analyzed by Langmuir and Freundlich models, that were considerably better suited for the investigated materials than other models. The process kinetics of CPF adsorbed onto both tested carbon versions were found to obey the pseudo first order at all concentrations with an exception at 70 mg/l using GAC, where, the spontaneous exothermic adsorption of Chlorpyrifos is a strong function for the pseudo-first order (PFO) and pseudo second order (PSO) kinetics.


2020 ◽  
Vol 9 (2) ◽  
pp. 108-116
Author(s):  
Tarmizi Taher ◽  
◽  
Nyanyu Ummu Hani ◽  
Neza Rahayu Palapa ◽  
Risfidian Mohadi ◽  
...  

In this work, two synthetic layered double hydroxides (LDH) consists of Zn2+ as M2+ cation with different M3+ cation, i.e., Al3+ and Cr3+ were used as an adsorbent for Congo Red removal aqueous solution. Both Zn-Al and Zn-Cr LDH were characterized by X-ray diffraction, FT-IR, and BET surface area analyzer. The effect of contact time, initial dye concentration, and temperature were evaluated in a batch technique in order to investigate the characteristic of Congo Red adsorption onto both adsorbents. The experimental data were assessed according to the parameter of adsorption kinetics, isotherm, and thermodynamics. The results of LDH characterization showed that Zn-Al LDH has a higher interlayer distance than Zn-Cr LDH, although Zn-Cr LDH has a higher surface area. The FT-IR analysis indicated the interlayer space of both Zn-Cr and Zn-Al LDH was dominated by CO32- as the interlayer anion species. The adsorption kinetics study of Congo Red on both LDH revealed that the adsorption process followed the pseudo-second-order model. For the adsorption isotherm, the experimental data fit well with the Freundlich model rather than the Langmuir model. The thermodynamic study indicated that the adsorption process that occurred on both adsorbents was spontaneous with exothermic nature.


2021 ◽  
Vol 37 (2) ◽  
pp. 444-449
Author(s):  
F. Janeeta Priya ◽  
A. Leema Rose ◽  
S. Vidhya ◽  
A Arputharaj ◽  
S. Akshana ◽  
...  

Latterly, the green synthesis of metallic nanoparticles has stock pile and terminal interest over the last decade due to their idiosyncratic properties that make them felicitous in various fields of science and technology. In this study the silver nanoparticles can be manufacture by using the leaf extract of Kalanchoe pinnata plant using microwave radiation method. The nanoparticles that are synthesized by plants are non-toxic and eco-friendly and it is characterized by using UV-Visible, FT-IR , X-ray diffraction (XRD) and TEM.The crystalline natures of the synthesized silver nanoparticles were identified by XRD and its shape was confirmed by TEM analysis. Anti-urolithiatic activity of synthesized silver nanoparticles was accomplished which reduces the growth of kidney stone which was appraisal by using the In-Vitro growth of urinary calculi.


Author(s):  
Bruna Assis Paim dos Santos ◽  
Aline Silva Cossolin ◽  
Hélen Cristina Oliveira dos Reis ◽  
Ketinny Camargo de Castro ◽  
Evanleide Rodrigues da Silva ◽  
...  

In this study, baker’s yeast-MnO2 composites, produced by direct oxidation of yeast with KMnO4 under acidic conditions, were used as biosorbent to remove the triphenylmethane dye Malachite green (MG) from an aqueous solution. Parameters that influence the adsorption process, such as pH, contact time, temperature, initial dye concentration and biosorbent dosage, were evaluated in batch experiments. The optimum removal of MG was found to be  86.7 mg g-1 at pH 10, 1.0 g L-1 of biomass dosage and 45°C. The kinetic data of dye removal was better described by the pseudo-second-order model. The adsorption process followed the Langmuir isotherm model and the maximum biosorption capacity was estimated to be  243.9 mg g-1 (at 25°C). The negative values of ∆G° and the positive value of ∆H° indicated that the MG biosorption onto yeast-MnO2 composites is spontaneous and endothermic. Fourier transform infrared spectroscopy (FTIR) indicated that the nano-MnO2 particles deposited on yeast-MnO2 composites surface facilitated the MG adsorption. It was concluded that baker’s yeast-MnO2 composites have potential for application as adsorbent for removal of MG from aqueous solution.


Crystals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 409
Author(s):  
Kuizhou Dou ◽  
Yinshan Jiang ◽  
Bing Xue ◽  
Cundi Wei ◽  
Fangfei Li

Rare-earth-doped SiAlON and Si3N4 materials from aluminosilicate starting materials have been reported to show superior photoluminescence (PL) properties. Three different starting materials, including pulverized coal furnace fly ash, diatomite and raw illite, were used for synthesis of nitride materials. The phase and morphology evolution of these products were carefully monitored at the low temperature range of 1350 °C to 1450 °C by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). The PL properties of Eu-doped nitride products were also comparatively characterized. The results show that the type of starting material affects the phase composition and the photoluminescence properties of products. The existence of aluminum and alkali metals could effectively promote nitridation reactions. Aluminum in the starting materials led to the formation of different aluminum-rich nitride phases. Thus, β-SiAlON could be achieved at a much lower temperature (1350 °C) using raw illite or fly ash containing the proper amount of aluminum. Additionally, excess aluminum led to the formation of corundum and 15R-SiAlON. The products from pulverized coal furnace fly ash had more prismatic particles, and the products from diatomite had more fibrous particles. With the progress of the nitridation process, the fibers were increased, becoming longer and straighter, and the prismatic particles were more obvious. The presence of aluminum in the starting materials led to a blue shift in the photoluminescence spectrum.


Author(s):  
Qingqing Liu ◽  
Xiaoyan Li

The activated MgO was synthesized by microwave homo-precipitator method and characterized by SEM, EDS and FT-IR methods. It was used to adsorption of U(VI) from aqueous solution with batch system. The paper discussed the effect of pH, temperature, contact time, adsorbent dose and initial U(VI) concentration on the adsorption. The results showed that activated MgO has good adsorption capacity for U(VI), the removal rate and equilibrium adsorption capacity reached 83.5% and 84.04mg·g−1 at pH 5.0, 15mg dose and 313K,respectively. The adsorption kinetics of U(VI) onto activated MgO were better fitted with pseudo-second-order kinetic.The adsorption isotherm data were fitted well to Freundlich isotherm model.The thermodynamic parameters showed that the adsorption process is endothermic and spontaneous.


2008 ◽  
Vol 8 (9) ◽  
pp. 4743-4746 ◽  
Author(s):  
Haldorai Yuvaraj ◽  
Min Hee Woo ◽  
Eun Ju Park ◽  
Yeong-Soon Gal ◽  
Kwon Taek Lim

Poly(3-octylthiophene) (P3OT)-titanium dioxide (TiO2) nanocomposite powder where TiO2 was embedded with homogeneous dispersion was synthesized by in-situ chemical oxidative polymerization of 3-octylthiophene in the presence of TiO2 nanoparticles in supercritical carbon dioxide (scCO2), using ferric chloride as the oxidant. The synthesized materials could be obtained as dry powder upon venting of CO2 after the polymerization. The composites were subsequently characterized by FT-IR spectroscopy, transmission electron microscopy (TEM), X-ray diffraction studies (XRD), thermogravimetric analysis (TGA) and photoluminescence (PL). The incorporation of TiO2 in the composite was endorsed by FT-IR studies. TGA revealed enhanced thermal stability of P3OT/TiO2 nanocomposite compared to 3-octylthiophene. TEM analysis showed that well dispersed TiO2 nanoparticles in the polymer matrix. Photoluminescence quenching increased with increasing TiO2 concentration in the composite.


Sign in / Sign up

Export Citation Format

Share Document