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1.
Sci Rep ; 14(1): 5711, 2024 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-38459201

RESUMO

This study aimed to investigate the biological activities of Lactobacillus gasseri SM 05 (L. gasseri) and Lacticaseibacillus casei subsp. casei PTCC 1608 (L. casei) in the black raspberry (Rubus dolichocarpus) juice (BRJ) environment, and also the anti-adhesion activity against Salmonella typhimurium (S. typhimurium) in fermented black raspberry juice (FBRJ). Results showed significant anti-adhesion activity in Caco-2 epithelial cells. In the anti-adhesion process, lactic acid bacteria (LAB) improve intestinal health by preventing the adhesion of pathogens. Adding LAB to BRJ produces metabolites with bacteriocin properties. Major findings of this research include improved intestinal health, improved antidiabetic properties, inhibition of degradation of amino acids, and increase in the nutritional value of foods that have been subjected to heat processing by preventing Maillard inhibition, and inhibition of oxidation of foodstuff by increased antioxidant activity of BRJ. Both species of Lactobacillus effectively controlled the growth of S. typhimurium during BRJ fermentation. Moreover, in all tests, as well as Maillard's and α-amylase inhibition, L. gasseri was more effective than L. casei. The phenolic and flavonoid compounds increased significantly after fermentation by both LAB (p < 0.05). Adding Stevia extract to FBRJ and performing the HHP process showed convenient protection of phenolic compounds compared to heat processing.


Assuntos
Lacticaseibacillus casei , Lactobacillus gasseri , Probióticos , Rubus , Stevia , Humanos , Fermentação , Células CACO-2 , Extratos Vegetais/farmacologia
2.
Environ Res ; 220: 115153, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36574802

RESUMO

This study reports a versatile process for the fabrication of a microporous heterogeneous palladium nanocatalyst on a novel spherical, biodegradable, and chemically/physically resistant catalyst support consisting of chitosan (CS) and cigarette waste-derived activated carbon (CAC). The physicochemical properties of the microporous Pd-CS-CAC nanocatalyst developed were successfully determined by FTIR, XRD, FE-SEM, TEM, BET, and EDS techniques. TEM studies showed that the average particle size of the synthesized Pd NPs was about 30 nm. The catalytic prowess of microporous Pd-CS-CAC was evaluated in the reduction/decolorization of various nitroarenes (2-nitroaniline (2-NA), 4-nitroaniline (4-NA), 4-nitrophenol (4-NP), and 4-nitro-o-phenylenediamine (4-NPD)) and organic dyes (methyl red (MR), methyl orange (MO), methylene blue (MB), congo red (CR), and rhodamine B (RhB)) in an aqueous medium in the presence of NaBH4 as the reducing agent at room temperature. The catalytic activities were studied by UV-Vis absorption spectroscopy of the supernatant at regular time intervals. The short reaction times, mild reaction conditions, high efficiency (100% conversion), easy separation, and excellent chemical stability of the catalyst due to its heterogeneity and reusability are the advantages of this method. The results of the tests showed that reduction/decolorization reactions were successfully carried out within 10-140 s due to the good catalytic ability of Pd-CS-CAC. Moreover, Pd-CS-CAC was reused for 5 consecutive times with no loss of the initial shape, size, and morphology, confirming that it was a sustainable and robust nanocatalyst.


Assuntos
Quitosana , Paládio , Paládio/química , Quitosana/química , Corantes/química , Vermelho Congo/química , Extratos Vegetais/química , Catálise
3.
Adv Colloid Interface Sci ; 301: 102599, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35066374

RESUMO

Due to the environmental pollution issues and the supply of drinking/clean water, removal of both inorganic and organic (particularly dyes, nitroarenes, and heavy metals) to non-dangerous products and useful compounds are very important transformations. The deployment of sustainable and eco-friendly nanomaterials with exceptional structural and unique features such as high efficiency and stability/recyclability, high surface/volume ratio, low-cost production routes has become a priority; nonetheless, numerous significant challenges/restrictions still remained unresolved. The immobilization of green synthesized metal nanoparticles (NPs) on the natural materials and biowaste generated templates have been analyzed widely as a greener approach due to their environmentally friendly preparation methods, earth-abundance, cost-effectiveness with low energy consumption, biocompatibility, as well as adjustability in various cases of biomolecules as bioreducing agents. Natural and biowaste materials are widely considered as important sources to fabricate greener and biosynthesized types of metal, metal oxide, and metal sulfide nanomaterials using plant extracts. Integrating green synthesized nanoparticles with various biotemplates offers new practical composites for mitigating environmental challenges. In this review, degradation of dyes, reduction of toxic nitrophenols, absorption of heavy metals, and other hazardous/toxic environmental pollutants from contaminated water bodies using biowaste- and nature-derived nanomaterials are highlighted.


Assuntos
Nanopartículas Metálicas , Metais Pesados , Nanoestruturas , Nanopartículas Metálicas/química , Nanoestruturas/química , Óxidos
4.
Int J Biol Macromol ; 192: 771-819, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634337

RESUMO

Heck cross-coupling reaction (HCR) is one of the few transition metal catalyzed CC bond-forming reactions, which has been considered as the most effective, direct, and atom economical synthetic method using various catalytic systems. Heck reaction is widely employed in numerous syntheses including preparation of pharmaceutical and biologically active compounds, agrochemicals, natural products, fine chemicals, etc. Commonly, Pd-based catalysts have been used in HCR. In recent decades, the application of biopolymers as natural and effective supports has received attention due to their being cost effective, abundance, and non-toxicity. In fact, recent studies demonstrated that biopolymer-based catalysts had high sorption capacities, chelating activities, versatility, and stability, which make them potentially applicable as green materials (supports) in HCR. These catalytic systems present high stability and recyclability after several cycles of reaction. This review aims at providing an overview of the current progresses made towards the application of various polysaccharide and gelatin-supported metal catalysts in HCR in recent years. Natural polymers such as starch, gum, pectin, chitin, chitosan, cellulose, alginate and gelatin have been used as natural supports for metal-based catalysts in HCR. Diverse aspects of the reactions, different methods of preparation and application of polysaccharide and gelatin-based catalysts and their reusability have been reviewed.


Assuntos
Alginatos/química , Celulose/química , Quitina/química , Quitosana/química , Gelatina/química , Pectinas/química , Gomas Vegetais/química , Amido/química , Alginatos/metabolismo , Biopolímeros/química , Catálise , Celulose/metabolismo , Técnicas de Química Sintética , Quitina/metabolismo , Quitosana/metabolismo , Gelatina/metabolismo , Redes e Vias Metabólicas , Estrutura Molecular , Acoplamento Oxidativo , Pectinas/metabolismo , Gomas Vegetais/metabolismo , Polissacarídeos/química , Amido/metabolismo
5.
Carbohydr Polym ; 251: 116986, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142558

RESUMO

Natural biopolymers, polymeric organic molecules produced by living organisms and/or renewable resources, are considered greener, sustainable, and eco-friendly materials. Natural polysaccharides comprising cellulose, chitin/chitosan, starch, gum, alginate, and pectin are sustainable materials owing to their outstanding structural features, abundant availability, and nontoxicity, ease of modification, biocompatibility, and promissing potentials. Plentiful polysaccharides have been utilized for making assorted (nano)catalysts in recent years; fabrication of polysaccharides-supported metal/metal oxide (nano)materials is one of the effective strategies in nanotechnology. Water is one of the world's foremost environmental stress concerns. Nanomaterial-adorned polysaccharides-based entities have functioned as novel and more efficient (nano)catalysts or sorbents in eliminating an array of aqueous pollutants and contaminants, including ionic metals and organic/inorganic pollutants from wastewater. This review encompasses recent advancements, trends and challenges for natural biopolymers assembled from renewable resources for exploitation in the production of starch, cellulose, pectin, gum, alginate, chitin and chitosan-derived (nano)materials.


Assuntos
Biopolímeros , Nanoestruturas , Purificação da Água/métodos , Adsorção , Alginatos , Catálise , Celulose , Quitina , Quitosana , Conservação dos Recursos Hídricos , Química Verde , Nanoestruturas/química , Nanotecnologia , Pectinas , Amido , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
6.
IET Nanobiotechnol ; 14(7): 623-627, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33010139

RESUMO

Agricultural commodities, particularly cereals can be contaminated with mycotoxins during the pre- and post-harvest stage. The main goal of this study was to evaluate the efficacy of magnetic zeolite nanocomposite (MZNC) as an adsorbent for the reduction of mycotoxins in barley flour. The MZNC is synthesised using an eco-friendly and efficient procedure and characterised by zeta potential, field emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The adsorbent amount that affects the adsorption capacity was optimised. Low amounts of the nanocomposite removed >99% of aflatoxins, 50% of ochratoxin A, 22% of zearalenone, and 1.8% of the deoxynivalenol from the contaminated sample and adsorption by MZNC was better than the natural zeolite; this phenomenon is related to the wide surface of nanocomposites. Results provide new insights into possible future research that could overcome the challenges of using nanotechnology to eliminate mycotoxins from agricultural products. It can be hoped that the presence of cheap and eco-friendly mycotoxin binders such as the MZNC that is synthesised and utilised in this research will help to produce secure food and feed products.


Assuntos
Aflatoxinas/química , Hordeum/efeitos dos fármacos , Micotoxinas/química , Nanotecnologia/métodos , Ocratoxinas/química , Tricotecenos/química , Zearalenona/química , Adsorção , Centaurea , Grão Comestível/química , Fenômenos Magnéticos , Microscopia Eletrônica de Varredura , Extratos Vegetais/química , Pós , Zeolitas
7.
Int J Biol Macromol ; 148: 265-275, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31935407

RESUMO

Hibiscus Rosasinensis L. extract mediated biosynthesis of Pd nanoparticles (NPs) and their deposition on the magnetic calcium lignosulfonate (MCaLig), as a simple and eco-friendly process for the preparation of Pd NPs@Fe3O4-lignin, is reported. The Pd NPs@Fe3O4-lignin was characterized by TEM, XRD, EDS, FE-SEM, FT-IR, VSM, and UV-Vis. The magnetic NPs were employed as exceptional catalysts in the catalytic reduction of Cr(VI) and Suzuki-Miyaura reaction between PhB(OH)2 and substituted aryl halides in EtOH:H2O as well as under ligand free conditions in the presence of K2CO3 with satisfactory product yields. Regeneration of the Pd NPs@Fe3O4-lignin was carried out by a magnet after the preparation of biphenyls. Catalytic efficiency retention was achieved after seven cycles.


Assuntos
Cromo/química , Compostos Férricos/química , Hibiscus/química , Lignina/química , Nanopartículas/química , Paládio/química , Extratos Vegetais/química , Compostos de Bifenilo/química , Catálise , Química Verde/métodos , Lignina/análogos & derivados , Magnetismo/métodos , Folhas de Planta/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
8.
Adv Colloid Interface Sci ; 276: 102103, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31978638

RESUMO

Among various metal nanoparticles, palladium nanoparticles (Pd NPs) are one of the most important and fascinating nanomaterials. An important concern about the preparation of Pd NPs is the formation of toxic by-products, dangerous wastes and harmful pollutants. The best solution to exclude and/or minimize these toxic substances is plant mediated biosynthesis of Pd NPs. Biogenic Pd-based NPs from plant extracts have been identified as valuable nanocatalysts in various catalytic reactions because of their excellent activities and selectivity. They have captured the attention of researchers owing to their economical, sustainable, green and eco-friendly nature. This review attempts to cover the recent progresses in the fabrication, characterization and broad applications of biogenic Pd NPs in environmental and catalytic systems. In addition, the stability of biosynthesized Pd NPs and mechanism of their formation are investigated.


Assuntos
Antibacterianos/farmacologia , Complexos de Coordenação/farmacologia , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/química , Paládio/farmacologia , Plantas/química , Antibacterianos/química , Antibacterianos/metabolismo , Catálise , Complexos de Coordenação/química , Complexos de Coordenação/metabolismo , Paládio/química , Paládio/metabolismo , Plantas/metabolismo
9.
IET Nanobiotechnol ; 13(2): 202-213, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31051452

RESUMO

For the first time, copper nanoparticles (Cu NPs) superficially deposited on reduced graphene oxide (rGO) using Euphorbia cheiradenia Boiss leaf aqueous media. A beneficial series of analytical methods was used to characterise E. cheiradenia Boiss leaf extract and involved nanostructures. The Cu/rGO nanocomposite (NC) obtained from the conversion of Cu2+ ions to Cu NPs and GO to rGO undergoes the plant extract and used as a heterogeneous and reusable nanocatalyst for the destruction of 4-nitrophenol, rhodamine B, methylene blue, methyl orange and congo red using sodium borohydride at ambient temperature. In addition, Cu/rGO NC has reusability for many times in the reduction reactions with no decreasing of its catalytic capability.


Assuntos
Cobre/química , Euphorbia/química , Grafite/química , Extratos Vegetais/metabolismo , Poluentes da Água , Corantes/análise , Corantes/química , Corantes/metabolismo , Cobre/metabolismo , Grafite/metabolismo , Química Verde , Nanopartículas Metálicas/química , Nitrofenóis/análise , Nitrofenóis/química , Nitrofenóis/metabolismo , Tamanho da Partícula , Processos Fotoquímicos , Extratos Vegetais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes da Água/análise , Poluentes da Água/química , Poluentes da Água/metabolismo
10.
Chem Rec ; 19(12): 2436-2479, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31021524

RESUMO

Among different metallic nanoparticles, sliver nanoparticles (Ag NPs) are one of the most essential and fascinating nanomaterials. Importantly, among the metal based nanoparticles, Ag NPs play a key role in various fields such as biomedicine, biosensors, catalysis, pharmaceuticals, nanoscience and nanotechnology, particularly in nanomedicine. A main concern about the chemical synthesis of Ag NPs is the production of hazardous chemicals and toxic wastes. To overcome this problem, many research studies have been carried out on the green synthesis of Ag NPs using green sources such as plant extracts, microorganisms and some biopolymers without formation of hazardous wastes. Among green sources, plants could be remarkably valuable to exploring the biosynthesis of Ag NPs. In this review, the green synthesis of Ag-based nanocatalysts such as Ag NPs, AgPd NPs, Au-Ag NPs, Ag/AgPd NPs, Ag/Cu NPs, Ag@AgCl NPs, Au-Ag@AgCl nanocomposite, Ag-Cr-AC nanocomposite and Ag NPs immobilized on various supports such as Natrolite zeolite, bone, ZnO, seashell, hazelnut shell, almond shell, SnO2 , perlite, ZrO2 , TiO2 , α-Al2 O3 , CeO2 , reduced graphene oxide (rGO), h-Fe2 O3 @SiO2 , and Fe3 O4 using numerous plant extracts as reducing and stabilizing agents in the absence of hazardous surfactant and capping agents has been focused. This work describes the state of the art and future challenges in the biosynthesis of Ag-based nanocatalysts. The fact about the application of living plants in metal nanoparticle (MNPs) industry is that it is a more economical and efficient biosynthesis biosynthetic procedure. In addition, the catalytic activities of the synthesized, Ag-based recyclable nanocatalysts using various plant extracts in several chemical reactions such as oxidation, reduction, coupling, cycloaddition, cyanation, epoxidation, hydration, degradation and hydrogenation reactions have bben extensively discussed.


Assuntos
Antibacterianos/biossíntese , Química Verde/métodos , Nanopartículas Metálicas/química , Plantas/química , Prata/química , Antibacterianos/química , Benzimidazóis/síntese química , Benzimidazóis/química , Catálise , Extratos Vegetais/química , Plantas/metabolismo , Quinolinas/síntese química , Quinolinas/química , Dióxido de Silício/química
11.
Chem Rec ; 19(2-3): 601-643, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30230690

RESUMO

Copper nanoparticles (NPs) are one of the most commercialized nanomaterials. From the standpoint of nanotechnology copper-based nanostructured materials have many applications in biological process, folk medicine, electronics, and industrial fields. With growing concern regarding the energy crisis and problems of chemical and physical procedures to prepare the metal nanoparticles, efforts for alternative traditional chemistry attracted particular considerations. A widespread of researches have studied on biological methods which do not generate hazardous waste and therefore, don't need the purification processes. Plants could be remarkably valuable to exploring the biogenic synthesis of metal nanoparticles. The aim of this review is to provide further insight in to connections between plant extracts and synthesis of copper NPs. The utilization of living plants for biosynthesis of metal nanoparticles (MNPs) is a cost-effective and eco-friendly procedure. To date, the obtained results demonstrated several aspects of the plant physiology and their relations to nanoparticle synthesis. This work describes the state of the art and future challenges in green synthesis of copper NPs. This review has proven recent elevation in the green synthesis of Cu NPs, CuO NPs, Cu2 O NPs, CuS NPs, CuAl2 O4 and immobilized copper nanoparticles on the numerous supports such as Natrolite, bentonite, perlite, ZnO, MgO, MnO2 , reduced graphene oxide (RGO), and Fe3 O4 by a wide range of plant extracts. Therefore, detailed description of green synthesis and stabilizing agents concerning copper nanoparticles using these green sources is presented. Also, the catalytic activities of synthesized Cu-based recyclable nanocatalysts using various plant extracts in several chemical reactions such as oxidation, reduction, hydration, cyanation, cycloaddition, and coupling reactions were consciously investigated.


Assuntos
Cobre/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Catálise , Química Verde , Plantas/química
12.
Comb Chem High Throughput Screen ; 20(9): 787-795, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29065826

RESUMO

OBJECTIVE: Palladium nanoparticles (Pd NPs) supported on the TiO2 NPs were prepared using Euphorbia thymifolia L. leaf extract. The Pd/TiO2 NPs were characterized by FESEM, EDS, TEM and XRD analysis and were used as nanocatalysts for the reduction of a variety of organic dyes. To the best of the author's knowledge, this study explains the first report to the synthesis of Pd/TiO2 NPs using Euphorbia thymifolia L. leaf extract. METHOD: 1.0 G of TiO2 was dispersed in 40 mL of 0.3 Mm PdCl2 solution and sonicated for 30 min. Then, 20 mL of the plant extract was mixed under continuous stirring at 60°C for 2 h. The prepared Pd/TiO2 NPs were centrifuged, washed and then dried. RESULTS: FESEM imaging showed the formation of NPs in the size range of 19-29 nm. The Pd/TiO2 NPs exhibited high activity towards the reduction of Methyl Orange, Congo red and Rhodamine B in the presence of NaBH4 in aqueous medium during 4, 1 and 54 s, respectively. CONCLUSION: The synthesis of the Pd/TiO2 NPs by this route is rapid, simple, less time consuming, environmentally safe and compatibility for medical and pharmaceutical applications because of minimizing the use of toxic or hazardous organic solvents and reagents. Furthermore, the biosyenthesized nanocatalyst can catalyze the reduction of organic dyes during short-time and can be recovered and recycled several times without significant loss of activity.


Assuntos
Compostos Azo/química , Vermelho Congo/química , Nanopartículas/química , Extratos Vegetais/química , Rodaminas/química , Euphorbia/química , Oxirredução , Óxidos/química , Paládio/química , Tamanho da Partícula , Folhas de Planta/química , Propriedades de Superfície , Titânio/química , Água/química
13.
IET Nanobiotechnol ; 11(5): 538-545, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28745286

RESUMO

This study demonstrates a clean, non-toxic and environment friendly synthetic strategy for the preparation of the Natrolite zeolite/Cu nanoparticles (NPs) using Natrolite zeolite as a natural support and Anthemis xylopoda flowers aqueous extract as a reducing and stabilising agent for the synthesis of Cu NPs. Cu NPs with 20 nm diameter were immobilised homogeneously on the surface of Natrolite zeolite. The synthesised Natrolite zeolite/Cu NPs was used as an environmentally benign catalyst for the reduction of 4-nitrophenol, congo red and methylene blue in aqueous media at an ambient temperature. It has been found that the catalyst can be reused several times without any decrease in activity.


Assuntos
Vermelho Congo/química , Cobre/química , Química Verde , Nanopartículas Metálicas/química , Azul de Metileno/química , Nitrofenóis/química , Silicatos/química , Zeolitas/química , Anthemis/química , Catálise , Flores/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Oxirredução , Extratos Vegetais/química , Espectrometria por Raios X , Termogravimetria
14.
J Colloid Interface Sci ; 506: 471-477, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28755642

RESUMO

Copper nanoparticles (Cu NPs) were synthesized via a green method by using of Plantago asiatica leaf extract as natural solvent and reaction biomedia under environmentally benign reaction conditions. It was observed that use of Plantago asiatica leaf extract makes a simple, eco-friendly and cost effective method for the preparation of the Cu NPs and can reduce copper ions into Cu(0) within 5min of reaction time without using any stabilizer or surfactant agent. The progress of the reaction was monitored using UV-Visible spectroscopy. Polyphenolics could be adsorbed on the surface of Cu NPs, possibly by interaction through π-electrons interaction in the absence of other strong ligating agents. The catalytic activity of the Cu NPs was evaluated by cyanation of aldehydes in the extract as a green solvent. This method provided several advantages such as cleaner easy work-up, shorter reaction time and higher yield. Cu NPs were characterized by FT-IR, UV-Vis, TEM, X-ray diffraction and the synthesized products were characterized by FT-IR and 1H NMR.


Assuntos
Aldeídos/química , Cobre/química , Ferrocianetos/química , Nanopartículas Metálicas/química , Extratos Vegetais/química , Catálise , Química Verde , Nitrilas/química , Oxirredução , Tamanho da Partícula , Folhas de Planta/química , Plantago/química , Propriedades de Superfície
15.
J Colloid Interface Sci ; 499: 93-101, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28364719

RESUMO

This study focuses on the green synthesis of the Ag/bone nanocomposite by using Myrica gale L. aqueous extract as a reducing and stabilizing agent and investigation of its catalytic activity in the hydration of cyanamides under environmentally benign reaction conditions in aqueous extract as a green solvent without use of toxic and hazardous chemicals. The green synthesized Ag/bone nanocomposite was characterized by various analytical techniques such as X-ray diffraction analysis (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) images, energy-dispersive X-ray spectroscopy (EDS), elemental mapping, and FT-IR spectroscopy. The advantages of this system include the use of green catalyst, benign reaction conditions without use of expensive and hazardous materials, easy work up, reusability of the catalyst and excellent yield of the products. The Ag/bone nanocomposite can be recovered and recycled several times without significant loss of activity.


Assuntos
Osso e Ossos/química , Cianamida/química , Myrica/química , Nanocompostos/química , Extratos Vegetais/química , Prata/química , Catálise , Química Verde/métodos , Tamanho da Partícula , Folhas de Planta/química , Solventes/química , Propriedades de Superfície , Água
16.
J Colloid Interface Sci ; 497: 1-13, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28260670

RESUMO

In this work, the Ag/Fe3O4 nanocomposite was prepared by Euphorbia peplus Linn (L.) leaf extract as a suitable reducing source and stabilizing agent. The green synthesized nanocomposite was characterized using X-ray diffraction analysis (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) images, energy-dispersive X-ray spectroscopy (EDS) and FT-IR spectroscopy. TEM analysis of Ag/Fe3O4 nanocomposite showed the spherical shape nanoparticles (NPs) with an average size of 5-10nm. The Ag/Fe3O4 nanocomposite then was used as a magnetically recoverable catalyst for the [2+3] cycloaddition of arylcyanamides and sodium azide in high yields and short reaction times without formation of hydrazoic acid (HN3). Also it can be easily recovered via applying of external magnetic field and reused several times without significant loss of activity.


Assuntos
Euphorbia/química , Química Verde , Nanocompostos/química , Extratos Vegetais/química , Folhas de Planta/química , Nanocompostos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
17.
J Colloid Interface Sci ; 497: 33-42, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28260673

RESUMO

In current research, Ag/RGO/Fe3O4 nanocomposite was synthesized through applying the aqueous extract of Lotus garcinii leaves through a two-step method. The plant extract was utilized as agents for reduction and stabilization in biosynthesizing nanocomposite. The green synthesized nanocatalyst was characterized by FT-IR, FE-SEM, EDX, XRD, TEM, UV-Vis absorption spectroscopy. The catalytic activity of the biosynthesized nanocomposite was studied by reducing different colored solutions contained organic pollutants such as 4-nitrophenol (4-NP), Congo red (CR) and Rhodamine B (RhB). In order to verify commercial applications of the prepared heterogeneous nanocatalyst, reusability and recoverability tests were performed in five successive catalytic reactions.


Assuntos
Corantes/química , Óxido Ferroso-Férrico/química , Grafite/química , Lotus/química , Nitrofenóis/química , Extratos Vegetais/metabolismo , Prata/química , Catálise , Óxido Ferroso-Férrico/metabolismo , Grafite/metabolismo , Lotus/metabolismo , Oxirredução , Extratos Vegetais/química
18.
J Colloid Interface Sci ; 493: 85-93, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28088570

RESUMO

In this paper, silver nanoparticles (Ag NPs) are synthesized using Achillea millefolium L. extract as reducing and stabilizing agents and peach kernel shell as an environmentally benign support. FT-IR spectroscopy, UV-Vis spectroscopy, X-ray Diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), Thermo gravimetric-differential thermal analysis (TG-DTA) and Transmission Electron Microscopy (TEM) were used to characterize peach kernel shell, Ag NPs, and Ag NPs/peach kernel shell. The catalytic activity of the Ag NPs/peach kernel shell was investigated for the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), and Methylene Blue (MB) at room temperature. Ag NPs/peach kernel shell was found to be a highly active catalyst. In addition, Ag NPs/peach kernel shell can be recovered and reused several times with no significant loss of its catalytic activity.


Assuntos
Achillea/química , Corantes/química , Química Verde , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prunus persica/química , Prata/química , Água/química , Catálise , Oxirredução , Reciclagem
19.
J Colloid Interface Sci ; 490: 1-10, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27870949

RESUMO

For the first time the extract of the plant of Salvia hydrangea was used to green synthesis of Pd nanoparticles (NPs) supported on Apricot kernel shell as an environmentally benign support. The Pd NPs/Apricot kernel shell as an effective catalyst was prepared through reduction of Pd2+ ions using Salvia hydrangea extract as the reducing and capping agent and Pd NPs immobilization on Apricot kernel shell surface in the absence of any stabilizer or surfactant. According to FT-IR analysis, the hydroxyl groups of phenolics in Salvia hydrangea extract as bioreductant agents are directly responsible for the reduction of Pd2+ ions and formation of Pd NPs. The as-prepared catalyst was characterized by Fourier transform infrared (FT-IR) and UV-Vis spectroscopy, field emission scanning electron microscopy (FESEM) equipped with an energy dispersive X-ray spectroscopy (EDS), Elemental mapping, X-ray diffraction analysis (XRD) and transmittance electron microscopy (TEM). The synthesized catalyst was used in the reduction of 4-nitrophenol (4-NP), Methyl Orange (MO), Methylene Blue (MB), Rhodamine B (RhB), and Congo Red (CR) at room temperature. The Pd NPs/Apricot kernel shell showed excellent catalytic activity in the reduction of these organic dyes. In addition, it was found that Pd NPs/Apricot kernel shell can be recovered and reused several times without significant loss of catalytic activity.


Assuntos
Corantes/química , Química Verde/métodos , Nanopartículas Metálicas/química , Paládio/química , Prunus armeniaca/química , Salvia/química , Compostos Azo/química , Catálise , Vermelho Congo/química , Nanopartículas Metálicas/ultraestrutura , Azul de Metileno/química , Nanotecnologia/métodos , Nitrofenóis/química , Oxirredução , Extratos Vegetais/química , Rodaminas/química
20.
J Colloid Interface Sci ; 472: 173-9, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27038280

RESUMO

A green synthesis process was developed for the preparation of the Cu/ZnO nanoparticles (NPs) using Euphorbia prolifera leaf extract as a mild, renewable and non-toxic reducing agent and efficient stabilizer without using dangerous, hazardous and toxic materials. The approach of biosynthesis appears to be cost efficient eco-friendly and easy alternative to conventional methods of the Cu/ZnO NPs synthesis. The Cu/ZnO NPs were characterized by FESEM, EDS, elemental mapping, TEM and XRD. TEM micrograph has shown the formation of Cu NPs with the size in the range of 5-17 nm. In addition, the synthesized Cu/ZnO NPs presented excellent catalytic activity for the degradation of Methylene blue (MB) and Congo red (CR) in the presence of NaBH4 in water at room temperature.


Assuntos
Cobre/química , Euphorbia/química , Química Verde , Nanopartículas/química , Substâncias Redutoras/química , Óxido de Zinco/química , Catálise , Vermelho Congo/química , Química Verde/métodos , Azul de Metileno/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Extratos Vegetais/química , Folhas de Planta/química
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