In Situ Stabilisation of Silver Nanoparticles at Chitosan-Functionalised Graphene Oxide for Reduction of 2,4-Dinitrophenol in Water

This investigation reports the in situ growth of silver nanoparticles onto covalently bonded graphene oxide-chitosan, which serve as supported nanocatalysts for the NaBH4 reduction of 2,4-dinitrophenol in aqueous systems. Fumaryl chloride reacted with chitosan in an acidic environment to yield a tailored polymeric material. The latter was, in turn, treated with the pre-synthesised graphene oxide sheets under acidic conditions to generate the GO-functionalised membrane (GO-FL-CS). The adsorption of Ag+ from aqueous media by GO-FL-CS yielded a set of membranes that were decorated with silver nanoparticles (Ag NPs@GO-FL-CS) without any reducing agent. Various analytical tools were used to characterise these composites, including Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface area analysis, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray analysis, inductively coupled plasma-mass spectrometry, and transmission electron microscopy. The silver-loaded materials were further used for the remediation of 2,4-dinitrophenol from aqueous solutions under batch operation. The BET analysis revealed that the functionalisation of GO with chitosan and Ag NPs (average size 20–60 nm) resulted in a three-fold increased surface area. The optimised catalyst (Ag mass loading 16.95%) displayed remarkable activity with an apparent pseudo-first-order rate constant of 13.5 × 10−3 min−1. The cyclic voltammetry experiment was conducted to determine the nitro-conversion pathway. The reusability/stability test showed no significant reduction efficiency of this metal-laden composite over six cycles. Findings from the study revealed that Ag NPs@GO-FL-CS could be employed as a low-cost and recyclable catalyst to convert toxic nitroaromatics in wastewater.

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In Situ Fabrication of Nanoscale Graphene Oxide/Polyaniline Composite and its Electrochemical Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.148-149.1547 ◽

2010 ◽

Vol 148-149 ◽

pp. 1547-1550 ◽

Cited By ~ 3

Author(s):

Hua Lan Wang ◽

Qing Li Hao ◽

Xi Feng Xia ◽

Zhi Jia Wang ◽

Jiao Tian ◽

...

Keyword(s):

Electron Microscopy ◽

Graphene Oxide ◽

Photoelectron Spectroscopy ◽

In Situ Polymerization ◽

Ammonium Persulfate ◽

Polymerization Process ◽

Electrochemical Test ◽

X Ray ◽

Transmission Electron

A graphene oxide/polyaniline composite was synthesized by an in situ polymerization process. This product was simply prepared in an ethylene glycol medium, using ammonium persulfate as oxidant in ice bath. The composite was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-Ray photoelectron spectroscopy, Raman spectroscopy and electrochemical test. The composite material showed a good electrochemical performance.

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Synthesis, Characterization and Photocatalytic Performance of Poly-3-Thenoic Acid/Cu-TiO2 Nanohybrid for Efficient Visible Light Assisted Degradation of Bismarck Brown R

Trends in Sciences ◽

10.48048/tis.2022.1715 ◽

2022 ◽

Vol 19 (1) ◽

pp. 1715

Author(s):

Imandi Manga Raju ◽

Tirukkovalluri Siva Rao ◽

Miditana Sankara Rao

Keyword(s):

Electron Microscopy ◽

Visible Light ◽

Surface Area ◽

Visible Light Irradiation ◽

Sol Gel ◽

Anatase Tio2 ◽

X Ray ◽

Ft Ir ◽

Nanohybrid Material

The present work reported on the synthesis and characterization of Poly-3-Thenoic acid/Cu-TiO2 nanohybrid (PCuT) for the photocatalytic degradation of organic azo dye pollutant from wastewater. The as-synthesized nanohybrid by an in-situ modified sol-gel method including chemical oxidative polymerization was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, UV-visible diffuse reflectance spectroscopy (UV-vis.DRS), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and Brunauer-Emmet-Teller (BET) surface area analysis. The characterization results revealed the formation of small aggregates of polymer contained high crystalline anatase TiO2 nanoparticles (XRD) with narrowed bandgap energy (UV-vis.DRS), decreased particle size (TEM) with smooth surface morphology (SEM) and large surface area (BET). All the constituent elements of the polymer and Cu-TiO2 were found in the PCuT nanohybrid material (EDX) and their chemical interaction studied by FT-IR confirmed the stability of the nanohybrid. The photocatalytic activity of the nanohybrid was tested by the degradation of Bismarck Brown R dye under visible light irradiation. To enhance the photocatalytic efficiency, effects of various catalyst/dye reaction parameters such as polymer content, solution pH, catalyst dosage, and initial dye concentration were studied and optimized. HIGHLIGHTS Poly-3-Thenoic acid/Cu-TiO2 nanohybrid material was successfully synthesized by in situ modified sol-gel process Poly-3-Thenoic acid has enhanced the visible light absorption capacity of anatase TiO2 in nanohybrids Electron-hole recombination in TiO2 was effectively inhibited by Cu doping Bismark Brown R, an organic pollutant was successfully degraded in 75 min of visible light irradiation GRAPHICAL ABSTRACT

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Silver Nanoparticles: Green Synthesis, Characterization, Blood Compatibility and Protoscolicidal Efficacy against Echinococcus granulosus

Pakistan Veterinary Journal ◽

10.29261/pakvetj/2021.039 ◽

2021 ◽

Vol 41 (03) ◽

pp. 393-399

Author(s):

Parwin Jalal Jalil

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Silver Nanoparticles ◽

Echinococcus Granulosus ◽

Blood Compatibility ◽

Ag Nps ◽

X Ray ◽

Hydatid Fluid ◽

Scanning Electron

Spillage of protoscoleces within hydatid fluid during surgery for hydatid cyst is the main reason for its recurrence. Therefore, to inactivate the protoscoleces, various scolicidal substances have been tested. However, novel and more efficient agents are needed owing to several associated complications. This study focused on the effects of green synthetic Silver Nanoparticles (AgNPs) from Zizyphus spina- christi leaves on Echinococcus granulosus protoscoleces. Also, to evaluate the blood compatibility of Ag NPs. The Ag NPs were identified by ultraviolet-visible (UV-Visible) spectrophotometer, X-ray diffraction (XRD), Scanning electron microscopy imaging, and Energy-dispersive X-ray spectroscopy (EDX). Hydatid fluid was aspirated aseptically from cysts of infected sheep liver. The protoscoleces were exposed to Ag NPs at several concentrations. Also, scanning electron microscopy for ultrastructural changes and in vitro erythrocytes lysis was performed. The Ag NPs were spherical; the particles' size reached 50 nm, and presented a surface plasmon peak around 460 nm. The current study's findings indicated the powerful in vitro scolicidal efficacy of the green biosynthesized AgNPs. Several morphological alterations were observed on the protoscoleces by optical and scanning electron microscopy. Lysis of RBCs at different doses of Ag NPs was significantly (P≤0.05) less than the positive control value, thus proposing its biocompatibility. This work suggests that chemicals like polyphenols present in the extract of Z. spina- christi act as reducing and stabilizers agents to create Ag NPs Nevertheless, further investigations are needed to investigate the Ag NPs scolicidial effects in animal models.

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Bactericidal and In-Vitro Cytotoxic Efficacy of Silver Nanoparticles (Ag-NPs) Fabricated by Endophytic Actinomycetes and Their Use as Coating for the Textile Fabrics

Nanomaterials ◽

10.3390/nano10102082 ◽

2020 ◽

Vol 10 (10) ◽

pp. 2082 ◽

Cited By ~ 4

Author(s):

Salem S. Salem ◽

Ehab F. EL-Belely ◽

Gniewko Niedbała ◽

Maryam M. Alnoman ◽

Saad El-Din Hassan ◽

...

Keyword(s):

Electron Microscopy ◽

Silver Nanoparticles ◽

Inhibition Zone ◽

In Vitro Cytotoxicity ◽

Ag Nps ◽

X Ray ◽

Vis Spectroscopy ◽

Ft Ir ◽

The Stability

An endophytic strain of Streptomyces antimycoticus L-1 was isolated from healthy medicinal plant leaves of Mentha longifolia L. and used for the green synthesis of silver nanoparticles (Ag-NPs), through the use of secreted enzymes and proteins. UV–vis spectroscopy, Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analyses of the Ag-NPs were carried out. The XRD, TEM, and FT-IR analysis results demonstrated the successful biosynthesis of crystalline, spherical Ag-NPs with a particle size of 13–40 nm. Further, the stability of the Ag-NPs was assessed by detecting the surface Plasmon resonance (SPR) at 415 nm for one month or by measuring the NPs surface charge (−19.2 mV) by zeta potential analysis (ζ). The green-synthesized Ag-NPs exhibited broad-spectrum antibacterial activity at different concentrations (6.25–100 ppm) against the pathogens Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium with a clear inhibition zone ranging from (9.5 ± 0.4) nm to (21.7 ± 1.0) mm. Furthermore, the green-synthesized Ag-NPs displayed high efficacy against the Caco-2 cancerous cell line (the half maximal inhibitory concentration (IC50) = 5.7 ± 0.2 ppm). With respect to antibacterial and in-vitro cytotoxicity analyses, the Ag-NPs concentration of 100 ppm was selected as a safe dose for loading onto cotton fabrics. The scanning electron microscopy connected with energy-dispersive X-ray spectroscopy (SEM-EDX) for the nano-finished fabrics showed the distribution of Ag-NPs as 2% of the total fabric elements. Moreover, the nano-finished fabrics exhibited more activity against pathogenic Gram-positive and Gram-negative bacteria, even after 10 washing cycles, indicating the stability of the treated fabrics.

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Pd NPs supported on halloysite functionalized with Schiff base as an efficient catalyst for Sonogashira reaction

Scientific Reports ◽

10.1038/s41598-021-85821-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mansoureh Daraie ◽

Majid M. Heravi ◽

Yalda Rangraz ◽

Zahra Besharati

Keyword(s):

Electron Microscopy ◽

Schiff Base ◽

Inductively Coupled Plasma ◽

Aqueous Media ◽

Optical Emission ◽

Sonogashira Reaction ◽

Emission Spectrometry ◽

Efficient Catalyst ◽

X Ray ◽

Catalytic Support

AbstractA hybrid system was designed and synthesized through reacting modified halloysite (Hal-Cl) with Schiff base (DAB-PC) and applied as catalytic support for anchoring Pd NPs to afford Pd@Hal-DAB-PC catalyst. The resultant material was well identified by various analyses including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction patterns (XRD), thermogravimetric analysis (TGA), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and inductively coupled plasma-optical emission spectrometry (ICP-OES) and revealed outstanding catalytic activity in the Sonogashira reaction in aqueous media. Also, This nanocatalyst was simply collected and recycled up to six runs with a slight drop in efficiency, indicating the durability of Pd@Hal-DAB-PC.

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Evaluation of Antimicrobial, Structural, Magnetic, and Thermal Potential of Silver Nanoparticles Anchored Polyaniline-Itaconic Acid-CuO Nanocomposites Synthesized From In-Situ Polymerization Method

10.21203/rs.3.rs-942668/v1 ◽

2021 ◽

Author(s):

Parthiban E ◽

Sudarsan S

Keyword(s):

Electron Microscopy ◽

Silver Nanoparticles ◽

Itaconic Acid ◽

In Situ Polymerization ◽

Polymeric Nanocomposites ◽

X Ray ◽

Betel Leaf ◽

Selected Area Electron Diffraction ◽

Transmission Electron

Abstract The silver nanoparticles (AgNPs) have been embedded within the itaconic acid (IA), polyaniline (PANi), and copper oxide (CuO) to form Ag@PANi-IA-CuO polymeric nanocomposites. In-situ polymerization of itaconic acid has been carried out in the presence of aniline monomers using anhydrous iron trichloride as an oxidising agent. The piper betel leaf extract was used to a reduction of AgNO3. The anchoring of AgNPs onto nanocomposite has been characterized using different techniques such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED) X-ray diffraction (XRD), and energy-dispersive X-ray (EDX). Biological, magnetic, and thermal properties of nanocomposites have also been studied in antimicrobial, vibrating sample magnetometer (VSM), and thermogravimetric analysis (TGA). Hence, these types of silver nanoparticles anchored polyaniline-itaconic acid-CuO nanocomposite has shown an attractive application in the field of biomedical and wastewater treatment.

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MORPHOLOGIES OF SILVER NANOPARTICLES (Ag NPs) SYNTHESIZED BY HYDROTHERMAL AND LASER ABLATION TECHNIQUES

Surface Review and Letters ◽

10.1142/s0218625x20500158 ◽

2020 ◽

Vol 27 (12) ◽

pp. 2050015

Author(s):

REHANA SHAHID ◽

SIDRA KHALID ◽

SHAMAILA SHAHZADI

Keyword(s):

Electron Microscopy ◽

Silver Nanoparticles ◽

Laser Ablation ◽

Hydrothermal Process ◽

Suitable Method ◽

Ag Nps ◽

Uniform Size ◽

X Ray ◽

Laser Ablation Method ◽

Transmission Electron

Silver nanoparticles (Ag NPs) are prepared using two different techniques namely hydrothermal and laser ablation methods. The purpose of this study is to find a more suitable method to prepare Ag NPs through comparison that can give stable and size-controlled silver nanoparticles. Techniques used for observations are X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Comparison of results exhibited that hydrothermal process is a more suitable method to prepare silver nanoparticles with smaller uniform size and better yield as compared to laser ablation method. Also, at low temperature, NPs obtained using hydrothermal process provide better control on morphology, high purity and narrow size distribution.

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Efficient Adsorption of Deoxynivalenol by Porous Carbon Prepared from Soybean Dreg

Toxins ◽

10.3390/toxins13070500 ◽

2021 ◽

Vol 13 (7) ◽

pp. 500

Author(s):

Zhiwei Ying ◽

Di Zhao ◽

He Li ◽

Xinqi Liu ◽

Jian Zhang

Keyword(s):

Electron Microscopy ◽

Specific Surface ◽

Adsorption Capacity ◽

Surface Area ◽

Specific Surface Area ◽

Porous Carbon ◽

Carbon Material ◽

Adsorption Effect ◽

X Ray ◽

Bet Analysis

A novel porous carbon adsorbent for the removal of deoxynivalenol was prepared from soybean dreg (SD). The new material was characterized by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, N2 adsorption/desorption measurement techniques, X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). The specific surface area of the SDB-6-KOH was found to be 3655.95 m2 g−1, the pore volume was 1.936 cm3 g−1 and the average pore size was 2.125 nm. The high specific surface area and effective functional groups of the carbon material promoted the adsorption of deoxynivalenol. By comparing the adsorption effect of SDB-6-X prepared with different activators (X: KOH, K2CO3, KHCO3), SDB-6-KOH had the highest adsorption capacity. The maximum adsorption capacity of SDB-6-KOH to deoxynivalenol was 52.9877 µg mg−1, and the removal efficiency reached 88.31% at 318 K. The adsorption kinetic and isotherm data were suitable for pseudo-second-order and Langmuir equations, and the results of this study show that the novel carbon material has excellent adsorptive ability and, thus, offers effective practical application potential for the removal of deoxynivalenol.

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Temperature-driven directional coalescence of silver nanoparticles

Journal of Synchrotron Radiation ◽

10.1107/s1600577516002253 ◽

2016 ◽

Vol 23 (3) ◽

pp. 718-728 ◽

Cited By ~ 1

Author(s):

Shi Yan ◽

Dongbai Sun ◽

Yu Gong ◽

Yuanyuan Tan ◽

Xueqing Xing ◽

...

Keyword(s):

Electron Microscopy ◽

Thermal Stability ◽

Silver Nanoparticles ◽

Thermal Expansion ◽

Thermal Expansion Coefficient ◽

Expansion Coefficient ◽

Temperature Dependent ◽

X Ray ◽

Nanoparticle Growth

Silver nanoparticles were synthesized with a chemical reduction method in the presence of polyvinylpyrrolidone as stabilizing agent. The thermal stability behavior of the silver nanoparticles was studied in the temperature range from 25 to 700°C. Thermal gravimetric analysis was used to measure the weight loss of the silver nanoparticles. Scanning electron microscopy and high-resolution transmission electron microscopy were used to observe the morphology and the change in shape of the silver nanoparticles.In situtemperature-dependent small-angle X-ray scattering was used to detect the increase in particle size with temperature.In situtemperature-dependent X-ray diffraction was used to characterize the increase in nanocrystal size and the thermal expansion coefficient. The results demonstrate that sequential slow and fast Ostward ripening are the main methods of nanoparticle growth at lower temperatures (<500°C), whereas successive random and directional coalescences are the main methods of nanoparticle growth at higher temperatures (>500°C). A four-stage model can be used to describe the whole sintering process. The thermal expansion coefficient (2.8 × 10−5 K−1) of silver nanoparticles is about 30% larger than that of bulk silver. To our knowledge, the temperature-driven directional coalescence of silver nanocrystals is reported for the first time. Two possible mechanisms of directional coalescence have been proposed. This study is of importance not only in terms of its fundamental academic interest but also in terms of the thermal stability of silver nanoparticles.

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Ag nanoparticles immobilized on new mesoporous triazine-based carbon (MTC) as green and recoverable catalyst for reduction of nitroaromatic in aqueous media

Scientific Reports ◽

10.1038/s41598-020-74232-4 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Narges Vahedi-Notash ◽

Majid M. Heravi ◽

Ali Alhampour ◽

Pourya Mohammadi

Keyword(s):

Electron Microscopy ◽

Inductively Coupled Plasma ◽

Aqueous Media ◽

Catalytic Efficiency ◽

Active Species ◽

X Ray Diffraction ◽

X Ray ◽

Inductively Coupled ◽

Transmission Electron ◽

Recoverable Catalyst

Abstract In this research, we reported an effective method for the synthesis of a new mesoporous triazine-based carbon (MTC) substrate and its application as the green and recoverable catalyst in the synthesis of organic compounds. The porous carbon acted as a substrate for silver active species after its surface modification by chloroacetonitrile (Ag@MTC). The Ag@MTC nanocatalyst was characterized by several techniques namely, Fourier-transform infrared spectroscopy, field emission scanning electron microscopy with energy dispersive spectroscopy, X-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller surface area analysis, and inductively coupled plasma. The Ag@MTC catalyst was applied for the reduction of nitroaromatic compounds in aqueous media by using NaBH4 (reducing agent) at room temperature. This nanocatalyst can be readily recovered and recycled for at least nine runs without a notable decrease in its efficiency. Catalytic efficiency studies exhibited that Ag@MTC nanocatalyst had good activity towards reduction reactions.

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