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Showing papers in "journal of nanostructure in chemistry in 2017"


Journal ArticleDOI
TL;DR: In this paper, the role of nanomaterials as effective adsorbents for wastewater purification is discussed and the challenges of cost-effective and environmentally acceptable nanOMaterials for water purification are discussed and reviewed.
Abstract: Nanomaterials have been extensively studied for heavy metal ions and dye removals from wastewater. This article reviews the role of nanomaterials as effective adsorbents for wastewater purification. In recent years, numerous novel nanomaterial adsorbents have been developed for enhancing the efficiency and adsorption capacities of removing contaminants from wastewater. The innovation, forthcoming development, and challenges of cost-effective and environmentally acceptable nanomaterials for water purification are discussed and reviewed in this article. This review concludes that nanomaterials have many unique morphological and structural properties that qualify them to be used as effective adsorbents to solve several environmental problems.

406 citations


Journal ArticleDOI
TL;DR: In this article, the same authors used a mixture of H2O2+HNO3 in a ratio of 1:3 (v/v) at 25°C.
Abstract: Water pollution is a worldwide issue for the eco-environment and human society. Removal of various pollutants including heavy metals from the environment is a big challenge. Techniques of adsorption are usually simple and work effectively. In the current study, MWCNTs were prepared by chemical vapor deposition (CVD) of acetylene at 600 °C. Fe–Co/CaCO3 catalyst/support was prepared by wet impregnation method. The crystal size of the catalyst was identified using XRD. Acidified functionalized multi-walled carbon nanotubes (MWCNT) were produced from oxidation of multi-walled carbon nanotubes by mixture of H2O2 + HNO3 in a ratio of 1:3 (v/v) at 25 °C. The structure and purity of synthesized functionalized CNTs were examined by TEM, N2-BET method and thermogravimetric analysis. The functional groups produced at CNTs surface were investigated using FTIR spectroscopy. Acidified functionalized MWCNTs with a high surface area of 194 m2g−1 and porous structure (17.19 nm) were used for water treatment from harmful cations (Pb2+, Cu2+, Ni2+ and Cd2+), single cation solutions and quaternary solution at different pH values and different times. The results were interesting because in single solutions the catalyst removed Pb2+, Ni2+, Cu2+ and Cd2+ with percentages of 93, 83, 78 and 15%, respectively, in 6 h. While in quaternary solution, adsorption was more complex and the order of the adsorbed metals was as following: Pb2+ (aq) > Cu2+(aq) > Cd2+ (aq) > Ni2+ (aq).

89 citations


Journal ArticleDOI
TL;DR: In this article, a single-step synthesis of GQDs using pyrolysis of citric acid was reported, where the effect of different pH was studied in detail to optimize the conditions of the formation of gQDs.
Abstract: Graphene quantum dots (GQDs) as a new series of nanomaterials have drawn great attention in recent years owning to their unique properties. Here we report the single-step synthesis of GQDs using pyrolysis of citric acid which produced GQDs at different pH. The effect of different pH was studied in detail to optimize the conditions of the formation of GQDs. UV–Visible absorption and normalized fluorescence spectra were applied to analyze the optical properties of GQDs. The particle size distribution of the GQDs in case of varying pH was determined to optimize the synthesis conditions. The surface morphology and microstructures were studied by atomic force microscope (AFM).

88 citations


Journal ArticleDOI
TL;DR: In this article, the size-controlled synthesis of silver nanoparticles via chemical reduction method by NaBH4 as reducing agent and poly(vinyl pyrrolidone) or PVP as stabilizing agent is reported.
Abstract: In this study, the size-controlled synthesis of silver nanoparticles (Ag NPs) via chemical reduction method by NaBH4 as a reducing agent and poly(vinyl pyrrolidone) or PVP as a stabilizing agent is reported. Changing of ratios between reducing agent and stabilizing agent relative to AgNO3-optimized conditions for synthesis of stable Ag NPs was studied. The formation of Ag NPs was tracked by UV–Vis spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectroscopy. Particle size distribution was studied by particle size analyzer, and the morphology was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The optical properties of the synthesized Ag NPs were also investigated. The optimized Ag NPs were very stable even after 1 month that was due to effective stabilization by PVP molecules. The mechanism of Ag NPs formation and stabilization is discussed in detail.

70 citations


Journal ArticleDOI
TL;DR: In this article, the doping of polyaniline (PANI) with graphene (G) and multi-walled carbon nanotubes (MWCNTs) by in situ polymerization was reported.
Abstract: This study reported the doping of polyaniline (PANI) with graphene (G) and multi-walled carbon nanotubes (MWCNTs) by in situ polymerization. The molecular structure of PANI and its composites was observed by FTIR, which shows that the intensity of composites peaks are higher than pure PANI due to charge transfer between the PANI and graphitic allotropes. The structural information and crystallinity of PANI and its composites can be deduced from X-ray diffraction. The morphological characterization was observed by transmission electron microscope, which elucidated that aniline molecules were physically adsorbed and polymerized on the surface of graphene and MWCNTs due to π–π* electron interaction. PANI represents as an external layer of composites with several diameters depending on the PANI deposition degree, where the cores are G and MWCNTs. The conductivity measurement clarified the conductivity value of 0.1 wt% G in PANI matrix is higher 17 times than PANI without it.

60 citations


Journal ArticleDOI
TL;DR: In this article, Nanosized manganese ferrite (MnFe2O4) particles were prepared by sol-gel method using natural polymers like wheat flour (WF) and potato flour (PF) as surfactants and its structural, morphological, optical and magnetic characteristics were studied by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), scanning electron microscope (SEM), photoluminescence spectrograph (PL) and vibration sample magnetometer (VSM).
Abstract: Nanosized manganese ferrite (MnFe2O4) particles were prepared by sol–gel method using natural polymers like wheat flour (WF) and potato flour (PF) as surfactants and its structural, morphological, optical and magnetic characteristics were studied by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), scanning electron microscope (SEM), photoluminescence spectroscopy (PL) and vibration sample magnetometer (VSM). Brunauer–Emmett–Teller (BET) surface area test also performed and the results obtained were discussed. The average crystallite size was found to be 23 and 16 nm for WF/MnFe2O4 and PF/MnFe2O4 samples, respectively. Magnetic hysteresis loops confirmed the super-paramagnetic behavior for both the samples. For oxidation of benzyl alcohol to benzaldehyde, the catalytic activity of MnFe2O4 nanoparticles (NPs) was carried out. Antimicrobial and antifungal activity of WF/MnFe2O4 and PF/MnFe2O4 samples were investigated against two Gram-positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae), two Gram-negative bacteria (Pseudomonas aeruginosa, Salmonella paratyphi) and fungus (Candida albicans) using inhibition zone method. Minimum Inhibitory Concentration (MIC) values also calculated to determine susceptibilities of bacteria to drugs and also to evaluate the activity of new antimicrobial agents. The in vitro cytotoxicity of newly synthesized samples were analyzed by MTT assay against MCF-7, A549 and HaCaT cell lines in a dose-dependent fashion. Among these two samples, sample B (using potato flour) shows better response than sample A (using wheat flour) and both the samples were non-toxic to normal cell line. The concentration required to kill 50% of the cell (IC50) was also calculated. MnFe2O4 nanoparticles were synthesized by sol–gel method using natural polymers, wheat flour and potato flour, as surfactant. The as-prepared MnFe2O4 was characterized by XRD, FT-IR, SEM, EDX, PL and VSM analysis. The average crystallite size was found to be 23 and 16 nm for WF/MnFe2O4 and PF/MnFe2O4 samples, respectively. Magnetic hysteresis loops confirmed the super-paramagnetic behavior for both the samples. The catalytic activity of MnFe2O4 nanoparticles (NPs) were carried out for oxidation of benzyl alcohol to benzaldehyde. Biological activities like antimicrobial, antifungal and anticancer activities of the samples were investigated. Among these two samples, PF/MnFe2O4 shows better response than WF/MnFe2O4 and both the samples were non-toxic to normal cell line. IC50 values of WF/MnFe2O4 (a) and PF/MnFe2O4 (b) against A549 and MCF-7 cell lines

58 citations


Journal ArticleDOI
TL;DR: The experiments demonstrate that the Cu@Chit NC synthesized via MVS using acetone was more effective than that of toluene in inhibiting fungal hyphae growth against R. solani AG-4 and S. rolfsii.
Abstract: In this report, the metal-vapor synthesis (MVS) was used for the preparation of copper nanoparticles which was then used for the preparation of chitosan–copper nanocomposite. The antifungal activity of Cu@Chit NCs against two sclerotium-forming plant pathogenic fungi Sclerotium rolfsii (S. rolfsii) and Rhizoctonia solani (R. solani) AG-4 was evaluated in vitro and their effects on hyphal morphology, and sclerotia formation were observed for the first time. The NCs were prepared through impregnation of chitosan with colloid solution of copper nanoparticles in organic solvent (acetone or toluene). Transmission electron microscopy shows that the particles have predominantly spherical form, polydisperse character, the mean diameter about 2–3 nm and a rather uniform distribution in the chitosan matrice. Analysis of the small angle scattering curves suggests that the copper particles in the NCs with the size of ≤2 nm are mostly located in the chitosan pores with the same size. The effect of Cu@Chit NCs on fungal growth reveals some significant inhibitory activity against two tested fungi. The highest level of inhibition against S. rolfsii and R. solani AG-4 was observed using the high concentrations of Cu@Chit NC prepared using acetone as a solvent. A loss of the cytoplasm content, cytoplasmic coagulation, irregular shape of mycelia, or destruction in the hyphae was confirmed. The experiments demonstrate that the Cu@Chit NC synthesized via MVS using acetone was more effective than that of toluene in inhibiting fungal hyphae growth against R. solani AG-4 and S. rolfsii. The results show that the Cu@Chit NCs are fungicidal against both the tested fungus at high concentrations and the fungicidal or fungistatic activity is dependent on the tested fungus species.

56 citations


Journal ArticleDOI
TL;DR: In this article, a review summarizes the applications of nano-ZnO as an efficient heterogeneous catalyst for the synthesis of diverse biologically relevant heterocycles reported so far and concludes that "the last decade has seen tremendous applications of the nano ZnO catalyst as a mild, cheap, efficient, commercially available, environmentally benign, non-toxic, reusable, heterogeneous catalyzer for the various organic transformations".
Abstract: Last decade has seen tremendous applications of nano-ZnO as a mild, cheap, efficient, commercially available, environmentally benign, non-toxic, reusable, heterogeneous catalyst for the various organic transformations. The present review summarizes the applications of nano-ZnO as an efficient heterogeneous catalyst for the synthesis of diverse biologically relevant heterocycles reported so far.

45 citations


Journal ArticleDOI
TL;DR: In this paper, a cotton leaf worm (Spodoptera littoralis) was treated with silica nanostructures and the mortality of treated larvaes by surface contact was faster than feeding bioassay method.
Abstract: Herein, silica nanostructures with various physicochemical characteristics were synthesized via surfactant-assisted methods. Potent entomotoxic effects of silica nanostructures were explored against cotton leaf worm (Spodoptera littoralis) for the first time by utilizing surface contact and feeding bioassay protocols. The mortality of the treated larvaes by surface contact was faster than feeding bioassay method. The results showed that the surface characteristics and particle size of silica nanostructures could effectively control their entomotoxic effects compared to commercial silica or even organic pesticides. It was also observed that the dead bodies of the insects became extremely dehydrated due to the damage of insect cuticular water barrier as a result of abrasion. Furthermore, the physical mode of action of silica nanostructures makes insects is unlikely to become physiologically resistant; hence, silica nanostructures can be efficiently used as a valuable tool in S. littoralis management programs.

32 citations


Journal ArticleDOI
TL;DR: In this article, the synthesis of Co(II) and Cr(III) Schiff base complexes obtained from thiourea has been investigated, where the complexes were used as precursors for preparation of Co3O4 and Cr2O3 nanoparticles via solid-state thermal decomposition without using a catalyst, toxic solvent, template or surfactant.
Abstract: This study focuses on the synthesis of Co(II) and Cr(III) Schiff base complexes obtained from thiourea. The complexes were synthesized by template method and characterized by elemental analysis (CHNS), FT-IR, UV–vis spectroscopy, conductivity measurement and magnetic moment. The spectroscopic studies suggested the octahedral and square-pyramidal structures for Co(II) and Cr(III) complexes, respectively. Then the complexes were used as precursors for preparation of Co3O4 and Cr2O3 nanoparticles via solid-state thermal decomposition without using a catalyst, toxic solvent, template or surfactant and complicated equipment, which makes it efficient, one-step, simple and environment-friendly. The chemical structure of the metal oxides is studied by FT-IR, XRD and SEM. To investigate the applications of the synthesized complexes, in the next step, the complexes were screened for antibacterial activity against clinically important bacteria such as Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The Cr(III) and Co(II) complexes showed good biological activity against all the tested bacteria. Also, the catalytic activities of the complexes were studied in toluene using non-toxic hydrogen peroxide as the oxidant. The results showed that Co(II) complex has catalytic activity for oxidation of toluene, but Cr(III) complex did not show any catalytic activity.

29 citations


Journal ArticleDOI
TL;DR: In this article, the efficiency of NiO/CNT nanocomposite to remove Pb2+ from aqueous solution is investigated using the direct coprecipitation method in the presence of CNTs.
Abstract: In this study, the efficiency of nickel oxide/carbon nanotube (NiO/CNT) nanocomposite to remove Pb2+ from aqueous solution is investigated. NiO/CNT nanocomposite was prepared using the direct coprecipitation method in an aqueous media in the presence of CNTs. Samples were characterized using simultaneous thermal analysis (STA), X-ray diffraction (XRD), filed emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET). To optimize the adsorption of Pb2+ ions on NiO/CNT nanocomposite, the effects of different parameters including pH, contact time, initial concentration of Pb2+, and adsorbent mass—were also investigated. The optimum Pb2+ removal efficiency on NiO/CNT nanocomposite is achieved under experimental conditions of pH 7, contact time of 10 min, initial Pb2+ concentration of 20 ppm, and adsorbent mass of 0.1 g. The experimental data showed that the Pb2+ ions adsorption of NiO/CNT nanocomposite was through a Freundlich isotherm model rather than a Langmuir model. The kinetic data of adsorption of Pb2+ ions on the adsorbent was perfectly shown by a pseudo-second-order equation, to indicate their chemical adsorption. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° were also measured; the obtained values showed that the adsorption was basically spontaneous and endothermic.

Journal ArticleDOI
TL;DR: A facile synthesis of Titanium dioxide (TiO2) nanoparticles by sol gel technique assisted by biogenic route using the rind of Aloevera is reported and the antibacterial assessment against human pathogens causing urinary tract infection is demonstrated.
Abstract: We report a facile synthesis of Titanium dioxide (TiO2) nanoparticles by sol gel technique assisted by biogenic route using the rind of Aloevera and demonstrate the antibacterial assessment against human pathogens causing urinary tract infection. The synthesized nanoparticles were characterized by powder XRD analysis, FT-IR analysis and scanning electron microscopic analysis. The XRD spectrum confirmed that the synthesized TiO2 nanoparticles exhibit anatase phase. Average grain size was calculated using Debye–Scherrer formula and it was found to decrease from 13 to 8 nm with increasing template concentration. FTIR spectrum showed characteristic bands at 1626, 1056 and 1074 cm−1 revealing C–N stretching of amino groups present in the protein cages of Aloevera which assist in the formation of TiO2 nanoparticles. Morphological characterization analyzed by SEM showed nanocoral network and all the networks displayed excellent invitro bioactivity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi and Proteus mirabilis. Drug delivery was assessed by the release of anti-inflammatory streptomycin which is evidenced by the release profile suggesting that it has the potential to provide better deliveries.

Journal ArticleDOI
TL;DR: In this paper, a new protocol for the synthesis of 2H-indazolo[2,1-b]phthalazine-trione derivatives is described via a one-pot three-component condensation reaction of phthalhydrazide, dimedone or 1,3-cyclohexanedione and aromatic aldehydes catalyzed by SnO2 nanoparticles as a heterogeneous catalyst under solvent-free conditions.
Abstract: A new protocol for the synthesis of 2H-indazolo[2,1-b]phthalazine-trione derivatives is described via a one-pot three-component condensation reaction of phthalhydrazide, dimedone or 1,3-cyclohexanedione and aromatic aldehydes catalyzed by SnO2 nanoparticles as a heterogeneous catalyst under solvent-free conditions. The SnO2 nanoparticles (NPs) were characterized by FT-IR, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analyzer (EDAX). The advantages of the protocol are the shorter reaction time, simple work-up procedure and reusable catalyst.

Journal ArticleDOI
TL;DR: In this article, a mesoporous silicate MCM-41, loaded with polypyrrole (PPy) and polyaniline (PAni) composites, was used for acid blue 62 removal from aqueous media.
Abstract: In this paper, we aimed to evaluate Acid Blue 62 removal from aqueous media, using mesoporous silicate MCM-41, loaded with polypyrrole (PPy) and polyaniline (PAni) composites. PPy/MCM-41 nanocomposite showed higher performance than PAni/MCM-41 due to its smaller molecule size. For characterizing the synthesized composites, different methods were applied. The Langmuir model showed the greatest agreement with the experimental findings (q m, 55.55 mg g−1). The kinetic study also confirmed the compatibility between the pseudo-second-order model and adsorption. Moreover, we measured Gibbs free energy changes (ΔG o) and enthalpy changes (ΔH o). Considering the negative ΔG o and positive ΔH o, AB62 adsorption on PPy/MCM-41 nanocomposite can be considered a spontaneous, endothermic reaction.

Journal ArticleDOI
TL;DR: In this article, a library of diverse chemically and medicinally important heterocyclic polyhydroquinoline derivatives was efficiently prepared via a one-pot multicomponent reaction starting from various raw materials including aromatic aldehydes, dimedone or 1,3-cyclohexandione, ethyl acetoacetate or methyl acetocacetate and ammonium acetate in the presence of Fe3O4/SiO2-OSO3H as a sulfonated silica-based magnetic nanocatalyst.
Abstract: In this work, a library of diverse chemically and medicinally important heterocyclic polyhydroquinoline derivatives was efficiently prepared via a one-pot multicomponent reaction starting from various raw materials including aromatic aldehydes, dimedone or 1,3-cyclohexandione, ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of Fe3O4/SiO2-OSO3H as a sulfonated silica-based magnetic nanocatalyst in high yields. Main advantages of the present practical approach are ready availability of starting materials, non-toxicity, inexpensiveness, ease of workup procedure, diversity orientation synthesis and an eco-friendly nature of the reaction. The nanocatalyst was characterized by Fourier transform infrared (FT-IR) spectra, scanning electron microscopy (SEM) images and energy-dispersive X-ray spectroscopy (EDX) spectra. The nanocatalyst was simply recovered using an external magnet and reused several times. Then, the pharmacological and biological activities of the products were theoretically examined by the prediction of activity spectra for substances (PASS) program.

Journal ArticleDOI
TL;DR: In this paper, the synthesis of bimetallic Pt@Cu nanostructures at elevated temperature of 100°C using Alchornea laxiflora leaf extract (ALLE) was reported.
Abstract: This study reports the synthesis of bimetallic Pt@Cu nanostructures at elevated temperature of 100 °C using Alchornea laxiflora leaf extract (ALLE). The nanostructures have been characterized using UV–vis spectroscopy, high resolution transmission electron microscopy (HRTEM), Fourier Transform Infrared spectroscopy (FTIR), energy dispersive X-ray(EDX) spectroscopy and X-ray diffraction (XRD) techniques. The sizes of the bimetallic Pt@Cu nanostructures range from 1.87 to 2.38 nm with an average particle size of 2.12 ± 0.21 nm, and they crystallized in face-centered cubic (fcc) symmetry. The EDX analysis confirms the bimetallism of Pt@Cu nanostructures and individual metals are present in the ratio 2:3. FTIR indicates strong peaks at 3427 cm−1 which is attributed to hydroxyl group of polyphenolic compounds in ALLE, and the peak disappeared completely in the FTIR of Pt@Cu nanostructures, thus confirming their significant roles in bioreduction process. Catalytic oxidative property of Pt@Cu nanostructures was investigated by oxidation of a model oil [dibenzothiophene (DBT) dissolved in n-heptane] to their corresponding sulfone. Our results show that bimetallic Pt@Cu nanostructures have higher catalytic oxidative activity than the conventional acetic acid that is used in the oxidative desulfurization process. The catalytic oxidative desulfurization activity shown by the Pt@Cu nanostructures promises the potential application in petroleum industry.

Journal ArticleDOI
TL;DR: In this article, the photocatalyst of Sm-ZnO-Ag was checked for the photodegradation of thiazin-type methylene blue (MB) dye in aqueous solution using light emitting diodes/solar illumination.
Abstract: The precipitation–decomposition method was used to prepare the photocatalyst (Sm–ZnO–Ag). Synthesized catalyst was characterized by X-ray diffraction, field emission scanning electron microscope images, and optical spectroscopy. The activity of photocatalyst of Sm–ZnO–Ag was checked for the photodegradation of thiazin-type methylene blue (MB) dye in aqueous solution using light emitting diodes/solar illumination. Sm–ZnO–Ag is found to be excellent competent than Ag–ZnO, Sm–ZnO and ZnO nanoparticles. The absorbance of ZnO was shifted into the visible region by the dopants (Ag and Sm). The influences of operational parameters such as initial pH, dose of photocatalyst and dye concentration on photomineralization of MB have been analyzed. Sunlight (16 min) gives excellent results in photocatalytic degradation compared to LED (80 min). The microbial zones of Sm–ZnO–Ag (Nps) showed free radical generation. The Sm–ZnO–Ag catalyst is stable and it’s reusable. A degradation mechanism is proposed for the photodegradation of MB under LED/solar light.

Journal ArticleDOI
TL;DR: In this article, an optimized homogeneous precipitation method was proposed for the synthesis of spherical and well-dispersed pure Ln2O2SO4 nanoparticles (NPs) using synthesized lanthanide sulfates and urea as starting materials.
Abstract: We have proposed an optimized homogeneous precipitation method for the synthesis of spherical and well-dispersed pure Ln2O2SO4 (Ln = Gd, Ho, Dy and Lu) nanoparticles (NPs) using synthesized lanthanide sulfates and urea as starting materials. Ln2O2SO4 NPs can be easily transformed to Ln2O2S by reduction under H2 flow at 650 °C for Gd, Dy and Ho whereas the reduction with Lu gave only Lu2O3. Particle size was between 500 nm and 3.5 µm. This reduction method allows to obtain Ln2O2S without using H2S which is highly toxic and uncomfortable gas. Ln2O2SO4/Ln2O2S synthetized can be used for release and oxygen storage or doped with luminescent centers for multimodal medical imaging applications.

Journal ArticleDOI
TL;DR: In this paper, the adaptive neural fuzzy inference system (ANFIS) was used for modeling of magnetic chitosan adsorption performance for the methyl orange removal, which revealed that the developed ANFIS models can effectively model the nonlinearity behavior of the adsorptive performance.
Abstract: In the present paper, the adaptive neural fuzzy inference system (ANFIS) was used for modeling of magnetic chitosan adsorption performance for the methyl orange removal. The ANFIS network, which is the best in data predicting, was trained with back propagation optimum method. Our results revealed that the developed ANFIS models can effectively model the non-linearity behavior of the adsorptive performance and the predicted values were in good agreement with the experimental data.

Journal ArticleDOI
TL;DR: In this article, a density functional theory study of the adsorption properties of NO2 and O3 molecules on heterostructured TiO2/ZnO nanocomposites is presented.
Abstract: We have presented a density functional theory study of the adsorption properties of NO2 and O3 molecules on heterostructured TiO2/ZnO nanocomposites. The most stable adsorption configurations, adsorption energies and charge transfers were calculated. The electronic properties of the complex TiO2/ZnO heterostructures were described using the density of states and molecular orbital analyses. For NO2 adsorption, it was found that the oxygen atoms preferentially move towards the fivefold coordinated titanium atoms, whereas the nitrogen atom binds to the zinc atom. In the case of O3 adsorption, the side oxygen atoms bind to the fivefold coordinated titanium sites, and the central oxygen atom does not contribute to the adsorption any longer. Thus, the interaction of NO2 and O3 molecules with TiO2 side of nanocomposite is strongly favored. On the N-doped TiO2/ZnO nanocomposites, the adsorption process is more energetically favorable than that on the pristine ones. The N-doped nanocomposites are far more sensitive to gas detection than the undoped ones. In TiO2/ZnO nanocomposites, the interactions of gas molecule and TiO2 are stronger than those between gas molecule and bare TiO2 nanoparticles, which reveals that ZnO is conducive to the interaction of NO2 and O3 molecules with TiO2 nanoparticles. Our theoretical results suggest multicomponent TiO2/ZnO nanocomposite as a potential material for gas sensing application.

Journal ArticleDOI
TL;DR: In this paper, the fibrillar poly(3-hexyl thiophene) single crystals were prepared from dilute solutions of toluene, xylene, and anisole, and were investigated from the perspective of structural properties.
Abstract: The fibrillar poly(3-hexyl thiophene) single crystals were prepared from dilute solutions of toluene, xylene, and anisole (0.01 wt%), and were investigated from the perspective of structural properties. Next, the rectangular and hexagonal poly(ethylene glycol) single crystals were developed from the dilute solutions and molten thin polymer films. The developing methodology used for all growth systems was self-seeding. The dimensions of fibrillar and rectangular/hexagonal single crystals ranged from several nanometers to some microns. Random single-co-crystals were also grown from dilute solution (0.018 wt% in amyl acetate) of crystalline–amorphous diblock copolymers and homopolymers. The small-angle X-ray scattering, grazing incidence wide-angle X-ray scattering, and atomic force microscopy analyses were employed to characterize prepared grained samples. The incident X-ray experiments demonstrated highly ordered and lamellar crystalline structures.

Journal ArticleDOI
TL;DR: The γ-Fe2O3@CuFAp nanocatalyst was synthesized and characterized by several methods including XRD, SEM, TEM, ICP, and FT-IR analyses.
Abstract: γ-Fe2O3@CuFAp nanocatalyst was synthesized and characterized by several methods including XRD, SEM, TEM, ICP, and FT-IR analyses. The γ-Fe2O3@CuFAp has been used as an efficient recyclable magnetic catalyst for synthesis of benzimidazoles. The γ-Fe2O3@CuFAp was conveniently separated from the reaction mixture by an external magnet, and could be reused at least 12 times without any considerable change in catalytic activity.

Journal ArticleDOI
TL;DR: In this paper, the interactions of nitrogen dioxide molecule with TiO2-supported Au nanoparticles were investigated using density functional theory, and the results indicated that NO2 adsorption by its oxygen atoms is energetically more favorable than its nitrogen atom.
Abstract: The interactions of nitrogen dioxide molecule with TiO2-supported Au nanoparticles were investigated using density functional theory Surface Au atoms on the TiO2-supported Au overlayer were found to be the most favorable binding sites, thus making the adsorption process very strong Both oxygen and nitrogen atoms of the NO2 molecule can bind to the Au surface by forming strong chemical bonds The adsorption of NO2 molecule on the considered structures gives rise to significant changes in the bond lengths, bond angles, and adsorption energies of the complex systems The results indicate that NO2 adsorption on the TiO2-supported Au nanoparticle by its oxygen atoms is energetically more favorable than the NO2 adsorption by its nitrogen atom, indicating the strong binding of NO2 to the TiO2-supported Au through its oxygen atoms Thus, the bridge configuration of TiO2/Au + NO2 is found to be the most stable configuration Both oxygen and nitrogen atoms of NO2 move favorably towards the Au surface, as confirmed by significant overlaps in the PDOSs of the atoms that forming chemical bonds This study not only suggests a theoretical basis for gas-sensing properties of the TiO2-supported Au nanoparticles, but also offers a rational approach to develop nanostructure-based chemical sensors with improved performance

Journal ArticleDOI
TL;DR: In this article, two functionals (B3LYP and ωB97XD) were used for density functional theory (DFT) calculation of two major boron compounds (BH3 and BF3) adsorption on fullerene-like Al12N12 nanocluster.
Abstract: In this study, two functionals (B3LYP and ωB97XD) were used for density functional theory (DFT) calculation of two major boron compounds (BH3 and BF3) adsorption on fullerene-like Al12N12 nanocluster. High values of adsorption energy, −268.6 (−244.7) for BF3 and −224.5 (−196.4) kJ/mol for BH3 were found using ωB97XD (B3LYP) functional, indicating strong chemisorption which is the result of Lewis acid–base interaction of adsorbent and adsorbates. The high negative values of ΔG (Gibbs free energy) and ΔH (enthalpy) confirm spontaneous exothermic adsorption process. Further studies were done by taking into account the charge analysis, FMO (frontier molecular orbitals), MEP (molecular electrostatic potential), density of states (DOS), and reactivity of resulted systems.

Journal ArticleDOI
TL;DR: In this paper, it has been reported that the production of defect free graphene is possible by the application of a kitchen mixer and the natural-surfactant role in the exfoliation mechanism has rarely been discussed.
Abstract: It has been reported that the production of defect free graphene is possible by the application of a kitchen mixer. Yet, we note that the natural-surfactant role in the exfoliation mechanism by a kitchen mixer has rarely been discussed. To investigate the possibility of graphene exfoliation in a bio-surfactant medium, we have produced graphene from the co-mixing of graphite and gum Arabic. Through the modelling of bulky graphite as a single composite disc, we have shown that the exfoliation of graphite crystal may be possible through rotational motion of graphite surface. In this paper, we also have developed two simple metric systems that were designed from the application of UV spectroscopy for in situ measurement of graphene sheet size after exfoliation step.

Journal ArticleDOI
TL;DR: In this paper, the synthesis of carbon-supported ZrO2 nanoparticles from zirconium oxyphthalocyanine (ZrOPc) and acetylacetonate [Zr(acac)4] using thermogravimetric analysis coupled with mass spectrometry (MS) was investigated.
Abstract: We report here the synthesis of carbon-supported ZrO2 nanoparticles from zirconium oxyphthalocyanine (ZrOPc) and acetylacetonate [Zr(acac)4]. Using thermogravimetric analysis (TGA) coupled with mass spectrometry (MS), we could investigate the thermal decomposition behavior of the chosen precursors. According to those results, we chose the heat treatment temperatures (T HT) using partial oxidizing (PO) and reducing (RED) atmosphere. By X-ray diffraction we detected structure and size of the nanoparticles; the size was further confirmed by transmission electron microscopy. ZrO2 formation happens at lower temperature with Zr(acac)4 than with ZrOPc, due to the lower thermal stability and a higher oxygen amount in Zr(acac)4. Using ZrOPc at T HT ≥900 °C, PO conditions facilitate the crystallite growth and formation of distinct tetragonal ZrO2, while with Zr(acac)4 a distinct tetragonal ZrO2 phase is observed already at T HT ≥750 °C in both RED and PO conditions. Tuning of ZrO2 nanocrystallite size from 5 to 9 nm by varying the precursor loading is also demonstrated. The chemical state of zirconium was analyzed by X-ray photoelectron spectroscopy, which confirms ZrO2 formation from different synthesis routes.

Journal ArticleDOI
TL;DR: In this article, a chemometric approach was applied for HSA nanoparticles' size optimization in order to improve the robustness of the HSA protein carrier for drug delivery in tumor interstitium.
Abstract: Human serum albumin (HSA), a versatile protein carrier for drug delivery, is an ideal material to fabricate nanoparticles for drug delivery systems. These nanoparticles can accumulate in tumor interstitium due to the enhanced permeability and retention effect. The most important characteristics of HSA nanoparticles are particle size, shape, and zeta potential. A chemometric approach was applied for HSA nanoparticles’ size optimization in this study. The effects of three experimental parameters; pressure (P) or power, organic solvent volume (V), and time (T), were investigated under sonication and high-pressure homogenization, using multivariate analysis. The trials were performed based on the Box–Behnken experimental design. The criteria for the appraisal of the descriptive ability of a multinomial were R 2 = 0.819, standard error = 20.420, and F-ratio = 19.550. The method was optimized with respect to the nanoparticles’ size as a response. The Box–Behnken experimental design was applied to optimize and trial the robustness of the HSA nanoparticle preparation method.

Journal ArticleDOI
TL;DR: In this paper, the structural, physical and electrical properties of nitroamine (NH2NO2) adsorption on the outer and inner surface of pristine and C-replacing boron nitride nanosheet were investigated at the B3LYP/6-31G (d) level of theory.
Abstract: The aims of this work is to scrutinize the structural, physical and electrical properties of nitroamine (NH2NO2) adsorption on the outer and inner surface of pristine and C-replacing boron nitride nanosheet (BN nanosheet), using density functional theory methods at cam-B3LYP/6-31G (d) level of theory. Inspections of determined results represent that the adsorption of nitramide on the outer surface of pristine and C-replaced BN nanosheet is exothermic and on the inner surface it is endothermic. The deformation energy of system displays that the geometry and structure of BN nanosheet and nitramide in the BN nanosheet/NH2NO2 complex change significantly from the original state, whereas the quantum parameters and gap energy of the BN nanosheet/NH2NO2 system alter slightly from the original state. The nuclear magnetic resonance and molecular electrostatic potential consequences exhibit that in the BN nanosheet/NH2NO2 complex, the highest density of electrons is concentrated surrounding the NH2NO2 molecule.

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TL;DR: In this article, a new catalyst prepared by supporting CoFe2O4 on copper slag (CS) and characterization of this catalyst was done with using scanning electron microscopy image, energy-dispersive X-ray spectroscopy, BET surface area, and Xray diffraction patterns.
Abstract: In this research, new catalyst prepared by supporting CoFe2O4 on copper slag (CS) and characterization of this catalyst was done with using scanning electron microscopy image, energy-dispersive X-ray spectroscopy, BET surface area, and X-ray diffraction patterns. UV + H2O2 processes by CoFe2O4/CS as a photocatalyst was used for degradation of 2-nitrophenol (2NP) as a pollutant in water. Response surface methodology in the Basis of a three-variable Box–Behnken design was applied to determine the effect of pH values (4, 7 and 10), concentration of 2-nitrophenol (10, 20 and 30 ppm), and concentration of H2O2 (30, 60 and 90 ppm) on the levels of response and optimized these operational parameters. The optimal conditions were determined as pH = 10, concentration of 2-nitrophenol = 10 ppm, and concentration of H2O2 = 90 ppm. Degradation efficiency in optimal condition was 96.55%.

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TL;DR: In this paper, a magnetically recoverable nanomaterial consisting of heteropoly acid supported on ionic liquid-modified copper ferrite nanoparticle was prepared and performed as a heterogeneous catalyst in the fast and convenient synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives under mild and solvent-free conditions.
Abstract: A novel, efficient and magnetically recoverable nanomaterial consisting of heteropoly acid supported on ionic liquid-modified copper ferrite nanoparticle was prepared and performed as a heterogeneous catalyst in the fast and convenient synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives under mild and solvent-free conditions. The synthesized nanomaterial was characterized with FT-IR, XRD, FESEM, TEM, ICP and VSM. Furthermore, the obtained nanomaterial displayed striking reusability in the titled catalytic reaction. Compared with the various previously reported catalysts, the newly synthesized nanocatalyst is found to be most efficient with regard to operation simplicity, reaction time, yield and ease of catalyst separation.