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•Preparation of the Ag/RGO/Fe3O4 nanocomposite using Lotus garcinii leaf extract.•Ag/RGO/Fe3O4 nanocomposite was used as a catalyst for the reduction of 4-nitrophenol and organic ...dyes.•Characterization of catalyst by FT-IR, FE-SEM, EDX, XRD, TEM, UV–Vis absorption spectroscopy.•The catalyst can be separated and reused for consecutive runs without any disruption in its activity.
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.
The synthesis of palladium nanoparticles (Pd NPs) using an aqueous extract of leaves of
Euphorbia thymifolia
L. and their application in the ligand-free Stille and Hiyama cross-coupling reactions are ...reported here. Pd NPs were characterized using powder XRD, TEM, FT-IR and UV-vis techniques. The synthesized Pd NPs exhibited excellent catalytic activity and the reactions generated the corresponding products in good to excellent yields. These methods have some advantages, such as efficiency, generality, high yield, elimination of ligand, organic solvent and homogeneous catalysts, cleaner reaction profiles, ease of product isolation and simplicity. The reactions were carried out in a green solvent
i.e.
water. The catalyst was quantitatively recovered and reused without significant loss in the catalytic activity.
The yields of the reaction products were very high and no toxic organic solvents were needed in this method. The high efficiency of the catalyst remains unaltered even after five successive cycles.
•Preparation of Au/Pd bimetallic nanoparticles as efficient and reusable catalysts.•The catalyst was investigated by SEM and EDS.•Ligand-free Suzuki coupling reactions.•Operational simplicity, ...elimination of ligand and homogeneous catalysts and high yields.
This communication reports on the synthesis and use of Au/Pd bimetallic nanoparticles, as separable catalysts for ligand-free Suzuki coupling reactions. This method has the advantages of high yields, elimination of homogeneous catalysts, green reaction conditions, simple methodology and easy work up. Catalytic efficiency remains unaltered even after several repeated cycles. The catalyst was characterized using the SEM and EDS.
Palladium nanoparticles (Pd NPs) supported on the TiO
NPs were prepared
using Euphorbia thymifolia L. leaf extract. The Pd/TiO
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/TiO
NPs using Euphorbia thymifolia L. leaf extract.
1.0 G of TiO
was dispersed in 40 mL of 0.3 Mm PdCl
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/TiO
NPs were centrifuged, washed and then dried.
FESEM imaging showed the formation of NPs in the size range of 19-29 nm. The Pd/TiO
NPs exhibited high activity towards the reduction of Methyl Orange, Congo red and Rhodamine B in
the presence of NaBH
in aqueous medium during 4, 1 and 54 s, respectively.
The synthesis of the Pd/TiO
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.
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•Polydopamine-coated magnetic Spirulina nanocomposite was successfully synthesized.•Nanocomposite was used for efficient adsorption of aflatoxins in pistachio.•Easy adsorbent ...separation from the sample matrix was achieved by a magnetic field.•Adsorption process including hydrogen bonding, hydrophobic and π-π interactions.•Comparative evaluations showed good figures of merit by the developed method.
An efficient adsorbent was synthesized and used in magnetic dispersive solid phase extraction (MDSPE) of aflatoxins B1, B2, G1, and G2 at trace levels in pistachio prior to analysis by HPLC equipped with a fluorescence detector. Spirulina (Sp) algae was first magnetized, followed by surface modification with dopamine (Dp). The adsorbent was characterized using FT-IR, XRD, FE-SEM, EDX, VSM, and BET analyses. The effects of different analytical parameters on the extraction performance were evaluated. Under optimal conditions, good limits of detection (LODs) and quantifications (LOQs) were achieved in the ranges of 0.02–0.07 and 0.06–0.21 ng g−1, respectively. The RSDs were 5.9, 6.3, 5.6, and 7.3% for AFB1, G1, B2, and G2, respectively. The proposed method was successfully used to determine AFs in pistachio samples and acceptable recoveries in the range of 72–95% were obtained.
•An eco-friendly, economical and easy work-up procedure to prepare Fe3O4/zeolite nanocomposite.•Characterization of the adsorbent using FE-SEM, EDX, FT-IR, XRD, BET, VSM, and zeta ...potential.•Effective and fast extraction of aflatoxins in rice samples.•Easy separation of adsorbent under an external magnetic field.
In this study, a magnetic nanocomposite was synthesized using a simple and efficient method, and its performance was evaluated through magnetic dispersive solid-phase extraction (MDSPE) of aflatoxins (AFs) in rice samples. The aqueous extract of Centaurea cyanus was used as a stabilizer and reducing agent in the synthesis of Fe3O4/zeolite nanocomposite. Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FT-IR), zeta potential, Brunauer–Emmett–Teller (BET), and vibrating sample magnetometer (VSM) were used to characterize the morphology of the adsorbent. The effects of nanocomposite dosage, vortex time, ionic strength, sample volume, and desorption conditions on the extraction efficiency of AFs were studied. The proposed nanocomposite showed excellent binding properties to AFs in the range of 2–10 ng g−1, and 82–96% of AFs were extracted within the first minute of contact. The limits of detection (LODs) were 0.1 and 0.02 ng g−1 for AFB1-AFG1 and AFB2-AFG2, respectively. Moreover, the limits of quantification (LOQs), were 0.4 and 0.08 ng g−1 for AFB1-AFG1 and AFB2-AFG2, respectively. Compared to other methods for the extraction and determination of AFs, the suggested MDSPE-LC/FD method possessed advantages such as rapidity, simplicity, excellent figures of merit, and eco-friendly nature.
A simple and environmentally friendly microextraction technique was used for determination of chlorpheniramine (CPM), an antihistamine drug, in human urine samples using dispersive liquid-liquid ...microextraction (DLLME) followed by high performance liquid chromatography with diode array detection (HPLC-DAD). In this extraction technique, an appropriate mixture of acetonitrile (disperser solvent) and carbon tetrachloride (extraction solvent) was rapidly injected into the urine sample containing the target analyte. Tiny droplets of extractant were formed and dispersed into the sample solution and then sedimented at the bottom of the conical test tube by centrifugation. Under optimal conditions, the calibration curve was linear in the range of 0.055-5.5 µg mL-1, with a detection limit of 16.5 ng mL-1. This proposed method was successfully applied to the analysis of real urine samples. Low consumption of toxic organic solvents, simplicity of operation, low cost and acceptable figures of merit are the main advantages of the proposed technique.
Utilizou-se uma técnica de microextração simples e ambientalmente amigável para a determinação de clorfeniramina (CPM), anti-histamínico, em amostras de urina humana, utilizando a microextração dispersiva líquido-líquido (DLLME), seguida por cromatografia líquida de alta eficiência com detecção por arranjo de diodos (HPLC-DAD). Nesse método de extração, mistura apropriada de acetonitrila (solvente dispersor) e tetracloreto de carbono (solvente de extração) foi injetada rapidamente na amostra de urina contendo o analito alvo. As pequenas gotículas de agente de extração foram formadas e dispersas na solução da amostra e, em seguida, sedimentadas no fundo do tubo cônico de ensaio por centrifugação. Em condições ótimas, a curva de calibração foi linear no intervalo entre 0,055 e 5,5 µg mL-1, com limite de detecção de 16,5 ng mL-1. O método proposto foi aplicado com sucesso na análise de amostras de urina reais. Baixo consumo de solventes orgânicos tóxicos, simplicidade de operação, baixo custo e figuras de mérito aceitáveis são as principais vantagens do método sugerido.
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•Rapid synthesis of the highly stable AuNPs using a few µL of Helicteres isora L.•The SEM images showed spherical AuNPs with diameters less than 25 nm.•AuNPs exhibited excellent free ...radical scavenging activity (IC50 = 4.98 ± 0.03 µg mL−1).•The time required to scavenge 50% DPPH free radicals was less than 20 min.
A quick and one-pot method for the green synthesis of gold nanoparticles (AuNPs) using small amounts of aqueous extract of Helicteres isora L. fruit has been developed. The results showed that by increasing the reaction temperature from ambient to 95 °C, the time required to synthesize AuNPs was reduced significantly. The SEM image clearly showed the formation of spherical AuNPs with narrow diameter distributions in the range of 6–25 nm. AuNPs exhibited excellent free radical scavenging activity (IC50 = 4.98 ± 0.03 µg mL−1) in a short time due to their large surface area.
We report the green synthesis of CuO nanoparticles (CuO NPs) using
Tamarix gallica
leaf extract and their catalytic activity for
N
-arylation of nitrogen-containing heterocycles with aryl halides ...under ligand-free conditions.
Tamarix gallica
leaves are used as a bio-material for the first time as reducing agent. The green synthesized CuO NPs was characterized using the powder XRD, TEM, UV-vis and FT-IR. This method offers several advantages,
viz.
high yields, simple methodology, recyclability of the catalyst and a simple workup procedure.
We report the green synthesis of CuO nanoparticles (CuO NPs) using
Tamarix gallica
leaf extract and their catalytic activity for
N
-arylation of nitrogen-containing heterocycles with aryl halides under ligand-free conditions.
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