Showing papers in "Journal of Inorganic and Organometallic Polymers and Materials in 2018"

Recent Advances in Electrochemical Performances of Graphene Composite (Graphene-Polyaniline/Polypyrrole/Activated Carbon/Carbon Nanotube) Electrode Materials for Supercapacitor: A Review

Abstract: The latest trend in the direction of miniaturized portable electronic devices has brought up necessitate for rechargeable energy sources Among the various non conventional energy devices, the supercapacitor is the promising candidate for gleaning the energy Supercapacitor, as a new energy device that colligates the gap between conventional capacitors and batteries, it has attracted more attention due to its high power density and long cycle life Many researchers work on, synthesizing new electrode material for the development of supercapacitor The electrode material possesses salient structure and electrochemical properties exhibit the efficient performance of the supercapacitor Graphene has high carrier mobility, thermal conductivity, elasticity and stiffness and also has a theoretical specific capacitance of 2630 m2g− 1 corresponds to a specific capacitance of 550 Fg− 1 This article summarizes and reviews the electrochemical performance and applications of various graphene composite materials such as graphene/polyaniline, graphene/polypyrrole, graphene/metal oxide, graphene/activated carbon, graphene/carbon nanotube as an electrode materials towards highly efficient supercapacitors and also dealt with symmetric, asymmetric and hybrid nature of the graphene based supercapacitor

Preparation of Metal–Organic Frameworks UiO-66 for Adsorptive Removal of Methotrexate from Aqueous Solution

Abstract: A low cytotoxic metal–organic framework (MOF) UiO-66 (UiO stands for University of Oslo) and NH2-UiO-66, that showed high cell viability of HFF-2 via 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyl tetrazolium assay, was reported as an effective adsorbent (antidotal) agents. The structure of MOFs was confirmed by Fourier transform infrared, Field emission scanning electron microscopy (FESEM) and X-ray diffraction. Thermal behavior of MOFs was investigated using with thermogravimetric analyzer in nitrogen atmosphere to check the thermal stability. FESEM showed NH2-UiO-66 displayed symmetrical crystals with triangular base pyramid morphology, with the particle size around 100 nm and uniform size distribution. The specific surface areas were calculated using the Brunauer–Emmett–Teller method and surface area and total pore volume of NH2-UiO-66 were calculated to be 1258 m2/g and 0.51 cm3/g, respectively. Methotrexate salt (MTX) was selected as the model drug which was adsorbed into inner pores and channels of MOFs by diffusion manner. The interaction between MOFs and MTX and the effect of pH on interaction between them in aqueous solution was investigated. The final results showed that UiO-66 have high adsorbing capacity and great affinity to MTX.

Synthesis and Electrochemical Studies of rGO/ZnO Nanocomposite for Supercapacitor Application

Abstract: Reduced graphene oxide (rGO) and zinc oxide (ZnO) have been widely studied for various applications due to their interesting physicochemical properties. In this work, we have synthesized ZnO and rGO/ZnO nanocomposite as an electrode material for supercapacitor application. A simple and cost effective method called ultrasonic-asisted solution process was used to synthesis rGO/ZnO nanocomposite. The prepared ZnO and rGO/ZnO nanocomposite were characterized by XRD, FESEM, TEM and confocal Raman. The XRD pattern substantiated the crystal structure of ZnO and formation of nanocomposite. The FESEM and TEM images demonstrate the embillshment of ZnO nanoparticles on the rGO sheets. The Raman analysis validated the hybridisation of nanocomposite. Further, the electrochemical studies of rGO/ZnO nanocomposite exhibited that the composite has the higher specific capacitance (312 F g−1) compared to pure ZnO (200 F g−1) with better cycling stability up to 1000 cycles. These findings revealed that the prepared rGO/ZnO nanocompositeisa better electrode material for suparcapacitor application.

A Review on Novel Eco-Friendly Green Approach to Synthesis TiO 2 Nanoparticles Using Different Extracts

Abstract: The inspiring applications of the metal oxide nanoparticles are capturing the interest of researchers worldwide. Different physical and chemical methods are being adapted to synthesize these nanoparticles. The green synthesis is a fruitful emerging process that is environment friendly and low-cost as well. During the last decade, a plenty of work on green synthesis of TiO2 nanoparticles had been practiced. In this review, a compact data on the green synthesis of TiO2 nanoparticles from the plant extracts is summarized. This review will also mention the amendable features for the qualitative and quantitative enhancement in the product and the reliable application perspectives.

The Temperature Effect on Magnetic Properties of NiFe2O4 Nanoparticles

Abstract: In this study, NiFe2O4 nanoparticles (NPs) were fabricated via auto citric acid sol–gel route at three different temperatures (900, 1000 and 1100 °C). X-ray diffraction (XRD) and Fourier transform infrared were utilized to analyze the structural properties of magnetic nanoparticles (MNPs). XRD patterns reflect the formation of spinel ferrites without the existence of any kind of secondary phases. Morphological features of resultant MNPs were characterized by scanning electron microscopy. The XRD results show that the crystallite size increases from 30.75 to 42.32 nm with increasing the temperature of the calcination process in a distinct linear trend. The enhancement of the saturation magnetization and magnetic moment of the uniaxial NiFe2O4 NPs were studied and varying from 35 to 40 emu/g and 1.47–1.68 µB, respectively, as the temperature increases. Mossbauer parameters for different calcination temperature have been determined. The occupation ratio of Ni2+ ions at the A sites decreases from 53 to 49% with increasing calcination temperature from 900 to 1100 °C.

WO 3 Nanostructures-Based Photocatalyst Approach Towards Degradation of RhB Dye

Abstract: Tungsten trioxide (WO3) was prepared from the precursor sodium tungstate (Na2WO4·2H2O) in the presence HCl by cost-effective and eco-friendly facile hydrothermal method at different operating temperature 120, 150, 180 and 210 °C during autoclave reaction. Different properties like morphology, optical properties, structure tailoring and degradation rate of prepared samples were studied by characterization like SEM, EDX, XRD and photocatalysis respectively. The photocatalytic activity test was examined to degrade RhB dye under visible light irradiation. Experimental results revealed the higher photocatalytic performance at 180 °C. The better photocatalytic activity obtained due to extended region of visible light, lower particle size, better morphology and lower recombination rate.

Nanosecond Pulsed Laser Ablation in Liquids as New Route for Preparing Polyvinyl Carbazole/Silver Nanoparticles Composite: Spectroscopic and Thermal Studies

Abstract: Silver nanoparticles (AgNPs) were synthesized by pulsed laser ablation in liquids technique (PLAL) using the laser parameter: irradiation time, power source and wavelength of nanosecond laser pulses. Nanocomposite films of poly (n-vinyl carbazole) (PVK) doped with synthesized AgNPs were prepared using casting method. Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) had been used to investigate the Spectroscopic and thermal characterizations of the prepared PVK/Ag nanocomposites samples. The IR spectra illustrated that there is a combination between PVK matrix and silver nanoparticles. Also, itillustrated that the band at 3052 cm−1 of PVK was shifted towards higher wavenumber by about (15–25) cm−1 at the time of irradiation 40 min, power 570 mW and wavelength 532 nm. SEM detected the existence of Ag nanoparticles that leading to changes in morphology of the surface. The thermodynamic parameters: activation energy $${{\text{E}}^{\text{*}}}$$ , entropy $$\Delta {{\text{S}}^{\text{*}}}$$ , enthalpy $$\Delta {{\text{H}}^{\text{*}}}$$ and Gibbs free energy $$\Delta {{\text{G}}^{\text{*}}}$$ that obtained from TG data in second decomposition step according to Coat’s–Redfern model were helpful in assigning the bond strength, ordering and thermal stability of the investigated samples. It was found the joint effect of both elevated temperature and coordination of Ag nanoparticles in PVK matrix were responsible for weakening and strengthening of the composite system.

Construction of MoS2/CND-WO3 Ternary Composite for Photocatalytic Hydrogen Evolution

Abstract: In the current work, photocatalysts with high efficiency and ability to drive under visible light were fabricated through the optimal incorporation of MoS2 into carbon nanodots (CND)-WO3 composites for hydrogen (H2) evolution through water splitting process under visible light illumination. XRD, SEM, EDX, BET, UV–vis absorption and photoluminescence emission (PL) spectroscopy were utilized to investigate the specific surface area, optical properties crystallographic structure, morphology, purity and elemental composition. The experimental results confirmed the monoclinic and hexagonal phase structure for composite nanostructures with average nanoparticle size of 8 nm. The efficient charge separation in ternary photocatalyst was confirmed through photoluminescence emission spectra. The photocatalytic performance of the ternary composite (1% MoS2/CND-WO3) was found superior when compared to that of pure and binary photocatalysts. However, further increase in concentration of MoS2 into composite has lessened the photocatalytic performance. The improved H2 evolution activity was ascribed to enhance efficiency of charge separation, extended region of visible-light absorption, strengthened W–O–C bonds, availability of more no. of active sites for reaction and high specific surface area. Considering our present study as cost-effective strategy, the as-synthesized photocatalysts can be favorable and give a new perspective for applied use in energy and environmental applications.

Synthesis and Magnetic Characterization of Cu Substituted Barium Hexaferrites

Abstract: Cu2+ ion substituted nanocrystalline BaFe12O19 [Ba1 − xCuxFe12O19 (0.0 ≤ x ≤ 0.5)] hexaferrite powders were synthesized by sol–gel combustion route and its effects on structure, morphology and magnetic properties of barium hexaferrite (BaFe12O19) were presented. X-Ray Powder Diffraction (XRD), Scanning Electron Microscopy (HR-SEM), Transmission Electron Microscopy (HR-TEM) and Fourier Transform Infrared (FT-IR) analyses revealed the M-type hexagonal structure of all samples. Vibrating sample magnetometer (VSM) analyses showed that all samples have strong ferromagnetic behavior at room temperature. The crystallite size varies in a range of 23.30–35.12 nm. Both HR-SEM and HR-TEM analyses confirmed the hexagonal morphology for products. A minimum of 40.49 and a maximum of 54.36 emu/g estimated specific saturation magnetization (σs) were observed for Ba0.5Cu0.5Fe12O19 and Ba0.9Cu0.1Fe12O19 NPs, respectively. The remnant magnetization (σr) has a minimum value of 21.27 emu/g belonging to Ba0.5Cu0.5Fe12O19 and has a maximum value of 28.15 emu/g belonging to Ba0.7Cu0.3Fe12O19 NPs. The coercive fields are between 1726 Oe and 2853 Oe. K eff (calculated effective anisotropy constants) is changing from 2.31 × 105 to 3.23 × 105 Ergs/g. It was observed that the strong magneto-crystalline anisotropy fields, (H a ) above 11.0 kOe for all samples which confirmed that all samples are hard magnet. Due to their small crystallite size (smaller than 50 nm) and high saturation magnetization, Ba1 − xCuxFe12O19 (0.0 ≤ x ≤ 0.5) nanoparticles can be employed as magnetic recording materials.

Anticancer Activity of Tamoxifen Loaded Tyrosine Decorated Biocompatible Fe3O4 Magnetic Nanoparticles Against Breast Cancer Cell Lines

Abstract: In this work we reported the synthesis of tamoxifen (TMX) loaded l-tyrosine natural amino acids (Tyr) modified Fe3O4 magnetic nanoparticles. Tyr, which was containing phenol groups was selected to study their effects on biocompatibility, loading capacity and release profile of TMX. TMX loaded Tyr modified Fe3O4 magnetic nanoparticles (F@Tyr@TMX NPs) were characterized by X-ray diffraction, thermo gravimetric analysis, Fourier transform infrared spectroscopy, vibrating sample magnetometer, dynamic light scattering and transmission electron microscopy techniques. The results showed that the ζ-potential of F@Tyr@TMX NPs was about − 12.8 mV and the average size was 22.19 ± 3.58 [mean ± SD (n = 50)] nm. The loading capacity of 11.34 ± 0.09% and encapsulation efficiency of 51.21 ± 0.41%. Additionally, hemolysis test and MTT assays on HEK-293 were performed for determination of biocompatibility of F@Tyr@TMX NPs. Finally, the anticancer activity of F@Tyr@TMX NPs studied on MCF-7 breast cancer cell lines. The results indicate that these as prepared magnetic nanoparticles are suitable for delivery of TMX and even other hydrophobic drugs.

Synthesis of Nanostructured Based WO3 Materials for Photocatalytic Applications

Abstract: In this article, a variety of well defined, highly symmetrical, and nanostructures of WO3 based materials were successfully synthesized through facile hydrothermal method at different reaction time 12, 18, 24, 30, and 36 h respectively. The as synthesized samples were characterized using SEM, EDX, XRD, BET, UV–Vis, and PL to investigate the morphology, purity and elemental composition of material, structural properties, surface area and optical properties respectively. SEM reveals that morphology of nanostructured materials have been significantly affected by varying the hydrothermal duration. XRD peaks show the monoclinic and hexagonal phase for a different reaction time, whereas EDX confirmed the purity of material. UV–Vis and PL confirmed the band edge position and high degradation rate. The as-prepared nanostructures also showed a very high specific surface area and proved an exceptional ability to eliminate organic pollutants. Experimental results showed that the efficient photocatalytic activity of methylene blue can be attributed to the carefully controlled hierarchical WO3 structures by modulating the surface morphology confirmed by PL and photocatalytic activity test as well.

Synthesis of Novel (Polymer Blend-Ceramics) Nanocomposites: Structural, Optical and Electrical Properties for Humidity Sensors

Abstract: Fabrication of novel nanocomposites films of (PVA–CMC) blend and (PVA–CMC) blend doped by niobium carbide nanoparticles has been investigated. The structural, optical and electrical properties of (PVA–CMC–NbC) nanocomposites for humidity sensors have been studied. The (PVA–CMC–NbC) nanocomposites were prepared with different concentrations of (polyvinyl alcohol and carboxyl methyl cellulose) and Niobium carbide nanoparticles. The experimental results of optical properties for (PVA–CMC–NbC) nanocomposites showed that the absorbance, absorption coefficient, extinction coefficient, refractive index, real and imaginary dielectric constants and optical conductivity of (PVA–CMC) blend increase with increase in Niobium carbide nanoparticles concentrations. The transmittance and energy band gap decrease with increase in Niobium carbide nanoparticles concentrations. The DC electrical properties of (PVA–CMC–NbC) nanocomposites showed that the electrical conductivity of the blend increases with increase in NbC nanoparticles concentrations. The experimental results of novel (PVA–CMC–NbC) nanocomposites applications showed that the (PVA–CMC–NbC) nanocomposites have high sensitivity for relative humidity.

Synthesis and Characterization of Antibacterial Activity of Spinel Chromium-Substituted Copper Ferrite Nanoparticles for Biomedical Application

Abstract: Metal ferrite nanoparticles (NPs) attracted much attention due to their superparamagnetic, catalytic properties and surface area to volume ratio. Among these spinel ferrite NPs have shown immense potential in nanomedicine. The objective of present research work was the synthesis of chromium-substituted spinel copper ferrite NPs [(CuCrxFe2−xO4 (0.0 ≤ x ≤ 1.0)] by coprecipitation method and characterization of their antibacterial activity against E. coli. The synthesized ferrite NPs were characterized by X-ray diffraction, FT-IR, UV- Vis diffuse reflectance, SEM, Brunauer-Emmett-Teller (BET) and Barrett–Joyner–Halenda (BJH) techniques. XRD analysis confirmed that the all the samples were cubic spinel in structure with crystal size of 43.3–20.2 nm. It has been found that as the amount of dopant (Cr) increases, size of the NPs decreased. The Eg values were found in the range of 1.20–1.80 eV for CuCrxFe2 − xO4 (0.0 ≤ x ≤ 1.0) NPs as analyzed by UV–Visible diffuse reflectance spectroscopy. The BET surface area of Cr-substituted ferrite NPs decreases as Cr content increased while the pore diameter increases when moved from CuFe2O4 to CuCrFeO2 analyzed by BJH. The antibacterial activity increases as the concentration of dopant (Cr) increased. It has been found that CuCrxFe2−xO4 NPs inhibit bacterial growth in a size dependent manner i.e., small size NPs (CuCrxFe2−xO4; 20.2 nm; x = 1.0) exhibit strong antibacterial activity (MIC; 2.5 mg/ml), whereas large size NPs (CuCrxFe2−xO4; 43.3 nm; x = 0.0) inhibit bacterial growth at concentration of more 16 mg/ml. SEM micrograph shows that CuCrxFe2−xO4 NPs get adhered to bacterial cell surfaces and damaged the cell membrane due to interaction between NPs and cell membrane. Cells treated with CuCrxFe2−xO4 NPs were irregular and abnormal in shape with distorted cell membrane. CuCrxFe2−xO4 NPs severely damaged E. coli cells might be because of formation of pits, indentation, deformation and distortion of cell wall and membrane, indicating significant loss of membrane integrity that may lead to cell death.

Antioxidant and Catalytic Activity of Biosynthesized CuO Nanoparticles Using Extract of Galeopsidis herba

Abstract: The main objective of this study was synthesis of CuO nanoparticles using extract of Galeopsidis herba and were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), SEM with EDS profile and transmission electron microscopy (TEM) analysis. SEM images confirmed that synthesized nanoparticles were spherical in nature. EDS profile confirmed the signal characteristic of cooper and oxygen. All the analyses revealed that synthesized CuO nanoparticles were 10 ± 5 nm in size. The antioxidant behavior of synthesized CuO nanoparticles was evaluated by scavenging free radicals of 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH). The DPPH scavenging activity was monitored using UV–Vis spectrophotometer. The synthesized CuO nanoparticles presented very good catalytic activity in the reduction of malachite green.

The Mixed Contribution of Ionic and Electronic Carriers to Conductivity in Chitosan Based Solid Electrolytes Mediated by CuNt Salt

Abstract: This work shows the contribution of both ionic and electronic conductivities in chitosan (CS) based solid polymer electrolytes incorporated with various amounts of copper nitrate (CuNt). The samples were prepared using solution cast technique. The second semicircles at intermediate frequency in impedance plots were observed. Surface plasmonic resonance (SPR) was illustrated from the UV–Vis spectrophotometry, where broad peaks at 702 nm were obtained as an evidence for nanoparticles formation. The second semicircles in the impedance plots and the distinguished SPR peaks have revealed the contribution of electronic conductivity in CS:CuNt based polymer electrolytes. The same trend of UV–Vis spectra at different temperatures reveals that CS:CuNt polymer electrolyte is thermally stable. The presence of electronic conductivity is the main shortcoming of copper ion conducting solid polymer electrolytes. The role of lattice energy of the copper salts on electrical properties and morphological (SEM) appearance was discussed. The TEM image shows Cu nanopartciles with various sizes. A stable SPR peak and vanishing of second semicircle at high temperatures reveals the stability of copper ion conducting chitosan based polymer electrolytes. The pattern of DC conductivity and dielectric constant as a function of salt concentration are almost found to be similar. Both estimated DC conductivities from AC spectra and those calculated from impedance plots are shown to be comparable. Highest DC conductivity of 3.65 × 10−5 S/cm has been achieved for the sample incorporated with 21 wt% of CuNt. The high value of dielectric constant at low frequency can be ascribed to electrode polarization. Electric modulus parameters are studied to understand the relaxation process. Two semicircles in Argand plots were separated.

Elucidation of Electrical and Optical Parameters of Poly(o-anthranilic acid)-poly(o-amino phenol)/Copper Oxide Nanocomposites Thin Films

Abstract: Copper oxide nanoparticles (CuO-NPs) are prepared based on thermal decomposition method. Polyanthranilic acid (PANA) and poly-o-aminophenol (POAP) are synthesized based on the oxidative polymerization in aqueous medium with potassium dichromate. Thin films are fabricated from PANA/POAP blends and composites of PANA/POAP with 0.25 and 0.40 wt% of CuO-NPs. The resulting thin films are characterized by different techniques such as XRD, SEM and UV–Vis absorption measurements. Surface morphology displays a good level of CuO-NPs distribution in POAP/PANA blends at 0.25 wt%. Initial agglomeration detects at 0.4 wt% concentration of CuO-NPs. It is found that the real dielectric constant (ereal) increases with increasing CuO-NPs content. Transmittance of PANA improves up to 95% in the presence of 50 wt% POAP. I–V characteristics of the PANA/POAP blend and nanocomposite films show a non-ohmic behavior. The obtained results indicate that the poly(o-anthranilic acid)-poly(o-amino phenol)/copper oxide nanocomposites thin film is a good candidate in optoelectronic devices based on its band gap and dispersion parameters.

Efficient Storage of Gentamicin in Nanoscale Zeolitic Imidazolate Framework-8 Nanocarrier for pH-Responsive Drug Release

Abstract: In this study, a simple method was developed to prepare gentamaicin (GEN)—loaded nanoscale zeolitic imidazolate framework-8 (GEN@NZIF-8) nanoparticles (NPs) at room temperature and GEN@NZIF-8 NPs were characterized by FT-IR spectroscopy, powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, BET nitrogen adsorption–desorption, and UV–Vis spectroscopy. The PXRD patterns showed that large drug molecules can be encapsulated in ZIF-8 frameworks. Thermogravimetric analysis confirms that the GEN@NZIF-8 NPs have higher thermal stability than ZIF-8 NPs. FT-IR spectroscopy exhibted the presence of functional groups of GEN and NZIF-8 frameworks in GEN@NZIF-8 NPs. Results showed that GEN@NZIF-8 NPs exhibited high drug capacity (19%) and high drug loading capacity of gentamicin anions through ion exchange and good chemical stability. The researchers attempted to demonstrate that large drug molecules at pH 5.0 and 7.4 could be loaded in NZIF-8 NPs. Additionally, drug release in acidic condition was faster than in physiological condition. The biological activities of GEN, NZIF-8 and GEN@NZIF-8 NPs against Gram-positive and Gram-negative bacteria showed that the GEN@NZIF-8 NPs had good antimicrobial activity. This work highlights the potential of using NZIF-8 as a valuable candidate to develop highly efficient drug delivery vehicles in the treatment of infectious diseases using pH-responsive release.

Gentamicin Loaded Zn2(bdc)2(dabco) Frameworks as Efficient Materials for Drug Delivery and Antibacterial Activity

Abstract: New drug delivery systems are very helpful in diagnosis and treatment of diseases through controlled and targeted drug delivery. They can increase bioavailability of drugs and reduce their side effects. Metal–organic frameworks (MOFs) are alternative drug delivery systems, which are suitable for targeted drug delivery due to their adjustable pore sizes and compatibility by adding some functional groups. Application of these compounds permits simultaneous use of several advantages including biocompatibility, the ability to absorb large amounts of drugs and control drug release. The present study was designed to provide Zn2(bdc)2(dabco) MOF and evaluate its performance in absorbing and releasing gentamicin. Characterization methods, such as FTIR, XRD, SEM, BET, UV–Vis spectroscopy and TGA, were employed to characterize the gentamicin-loaded Zn2(bdc)2(dabco) structure. The amount of drug release from Zn2(bdc)2(dabco) was measured in buffer solutions with 7.4 and 5.0 pHs. Furthermore, antibacterial properties of the drug, MOF and drug-loaded MOF have been investigated against Gram-positive and Gram-negative bacteria. This study shows the potential of using Zn2(bdc)2(dabco) frameworks for controlled release of antibiotic drugs.

Equilibrium, Kinetic and Thermodynamic Study of Magnetic Polyaniline/Graphene Oxide Based Nanocomposites for Ciprofloxacin Removal from Water

Abstract: In the present study, an adsorbent based on polyaniline-magnetic graphene oxide nanocomposite (MGO@PANI) was synthesized via in situ polymerization of an aniline monomer using ammonium persulfate as an oxidant in acidic medium for enhanced removal of ciprofloxacin (CIP) from aqueous solution. The surface functionality, morphology and elemental composition of the newly synthesized MGO@PANI were analyzed by FT-IR, FE-SEM, and EDX techniques. The adsorption efficacy of MGO@PANI was evaluated by monitoring the adsorption behavior of CIP antibiotic from aqueous samples. The effective factors on CIP adsorption such as solution pH, adsorbent dosage, contact time, concentration and temperature were investigated. The results revealed that MGO@PANI exhibits high adsorption efficiency with 97% removal of CIP (pH 6, dosage 20 mg, time 30 min at room temperature). The experimental data were well fitted to Freundlich adsorption isotherm suggesting multilayer pattern for adsorption process and the adsorption kinetics followed pseudo-second-order kinetics. Additionally, the thermodynamic study revealed that the CIP adsorption onto MGO@PANI was endothermic and indicated chemisorption mechanism.

Morphology Tailored Synthesis of C-WO 3 nanostructures and its Photocatalytic Application

Abstract: Photocatalytic degradation is an ambitious and cost effective technique used for decontamination and sanitization of the waste polluted water of environment. Hydrothermal method is used to synthesis the carbon coupled WO3 nanoparticles with different concentrations of carbon (0.0, 0.2, 0.5, 1.0 and 2.0%) from precursor Na2WO4·2H2O with glucose and nitric acid. Synthesized nanoparticles were characterized by SEM, EDX, XRD, UV–Vis, and PL to study morphology, and particle size, composition, structural and optical properties, respectively. SEM revealed that morphology of the carbon coupled WO3 nanoparticles becomes spherical by increasing amount of coupled carbon atoms. The average grain size of the carbon doped nanoparticles is found to be 15–20 nm. Furthermore, size of nanoparticles affect the band gap of synthesized nanoparticles as well. It has also been observed that carbon coupled WO3 nanoparticles effectively take part in photo degradation due to reduction of electron–hole recombination rate.

Synthesis and Application of Fe3O4@SiO2@Carboxyl-Terminated PAMAM Dendrimer Nanocomposite for Heavy Metal Removal

Abstract: In present study Fe3O4 magnetic nanoparticles (MNPs) were prepared using co-precipitation method. Prepared MNPs were coated by SiO2 layer via sol–gel process. Subsequent Michel-addition reaction and amidation were used to synthesize G3 polyamidoamine dendrimer on prepared Fe3O4@SiO2. Fe3O4@SiO2@ PAMAM dendrimer was reacted with monochloroacetic acid for preparation of final Fe3O4@SiO2@Carboxyl-terminated PAMAM dendrimer nanocomposite. Successful synthesis of Fe3O4@SiO2@Carboxyl-terminated PAMAM dendrimer nanocomposite was confirmed by FTIR spectroscopy and CHN analysis. The nanostructure of prepared composite MNPs was investigated using TEM. X-ray diffraction pattern and thermal stability of pure MNPs and composite MNPs were studied using XRD and TGA analysis respectively. Unmodified and modified MNPs were used as adsorbent for the removal of Cu(II), Cd(II) and Pb(II) form aqueous solutions. It was observed that the modification of MPNs enhances the ability of MPNs for removal of these heavy metals significantly. Also it was shown that this modification enhances the accessibility of MNPs to heavy metal ions at low concentrations.

Synthesis Characterization, Antimicrobial, Antioxidant, and Cytotoxic Activities of ZnO Nanorods on Reduced Graphene Oxide

Abstract: Zinc oxide (ZnO) nanorods decorated on reduced graphene oxide (RGO) nanocomposite was synthesized by one-pot hydrothermal synthesis. The morphology and the properties of the synthesized RGO–ZnO composites were characterized by XRD, FT-IR, Raman spectroscopy, FE-SEM-EDAX, HR-TEM, UV–Vis spectroscopy, and X-ray photo spectroscopy techniques. The antimicrobial properties of the graphene nanocomposite were examined against four different pathogens by agar well diffusion method, and antioxidant properties of the same were examined by four different free radical scavenging assays. It possessed no toxic effects on HEK293 Human embryonic kidney cell line. The synergistic effects between ZnO nanorods and RGO sheets enhanced the antimicrobial and antioxidant properties of the composite. The zinc ions in the solution dispersed on the RGO sheets enabled the intimate contact with microbes and induced the microbes to death. The results state that the RGO–ZnO nanocomposite exhibited remarkably enhanced antimicrobial efficacy and excellent cytotoxic property. The prepared RGO–ZnO nanocomposite was considered as a potent candidate for antibacterial and antioxidant activity.

Synthesis of Mesoporous Graphite Functionalized by Nitrogen for Efficient Removal of Safranin Dye Utilizing Rice Husk Ash; Equilibrium Studies and Response Surface Optimization

Abstract: Mesoporous graphitic carbon (PG) was successfully synthesized from alkaline treated rice husk ash through chemical activation by phosphoric acid at 800 °C for 1 h and modified by nitric acid to produce porous graphite with nitrogen functional group (N.PG). The morphology and structure of N.PGC were characterized by XRD, SEM and Micromeritics ASAP2010 analyzer at 77 K. N.PG was applied as an adsorbent material for safranin-O dye from aqueous solution. The removal of safranin dye by the synthetic porous graphite with nitrogen functional groups shows higher capacity as compared to the pure phase of porous graphite. The adsorption process was investigated as a function of contact time, adsorbent mass, pH, initial dye concentration and ionic strength. The kinetic studies revealed that the adsorption equilibrium was reached after 480 min and the obtained data well fitted with the pseudo-second-order kinetic model and Elovich kinetic model. The equilibrium adsorption isotherm of safranin by the synthetic N.PG was described with Langmuir isotherm model, and the calculated qmax is 20.66 mg/g. The removal process is highly dependent on the pH value of the solution, and the optimum pH for maximum removal of safranin-O is pH 6. The response surface methodology in conjunction with the central composite rotatable design was used to optimize the sorption process. From the second order polynomial model, the predicted optimum conditions for maximum removal of safranin (100%) are 365 min contact time, 0.3 g dose, 5 g/l NaCl and pH 6 at initial concentration 127 mg/l.

Effect of Li4Ti5O12 Nanoparticles on Structural, Optical and Thermal Properties of PVDF/PEO Blend

Abstract: Lithium titanate nanoparticles Li4Ti5O12 NPs were prepared by the solid-state reaction method using a stoichiometric ratio of lithium carbonate Li2CO3 and titanium oxide nanoparticles TiO2 NPs. X-ray diffraction (XRD) analysis confirmed the formation of Li4Ti5O12 NPs. High-resolution transmission electron microscope showed like—cube shape of Li4Ti5O12 NPs with an average particle size 42 nm. Poly(vinylidene fluoride) (PVDF) and poly(ethylene oxide) (PEO) (80/20 wt/wt%) blend doped with concentrations 0.5, 0.7, 1.0, 2.0, 5.0 and 7.0 wt% of Li4Ti5O12 NPs were prepared using casting technique. Structural, optical and thermal properties of polymer nanocomposites were investigated using XRD, high-resolution scanning electron microscope (HRSEM), energy dispersive spectrophotometer (EDS), Fourier transform infrared (FT-IR), ultraviolet–visible spectroscopy (UV–Vis) and differential scanning calorimetry (DSC). The XRD and FT-IR data showed that there was an interaction between the blend sample and Li4Ti5O12 NPs. Also, the addition of Li4Ti5O12 NPs decreased the degree of crystallinity of the blend sample. HRSEM images revealed that the presence of Li4Ti5O12 NPs changed the surface morphology of the nanocomposites and gave rise to crystalline domains up to 5 wt% Li4Ti5O12 NPs, then deteriorations was occurred.

Morphologically Controlled Synthesis of Cubes like Tin Oxide Nanoparticles and Study of its Application as Photocatalyst for Congo Red Degradation and as Fuel Additive

Abstract: Tin oxide nanocubes are synthesized by hydrothermal approach by using the stannic chloride as precursor salt and sodium hydroxide as precipitating agent in aqueous media. Synthesized product is analyzed by various techniques: X-ray powder diffraction analysis (XRD) and scanning electron microscopy (SEM). Structural composition and parameters of the product are analyzed by (XRD). Morphology of the product is analyzed by (SEM). These synthesized nanocubes are used in two applications: (1) as a photocatalyst and (2) as a fuel additive. Synthesized nanoparticles are used as photocatalyst for the degradation of an organic dye (Congo red) in aqueous medium. Photocatalytic degradation kinetics of dye is monitored at different concentrations of hydrogen peroxide and catalyst in the presence of sunlight. The percentage conversion of dye is also calculated for different concentrations of hydrogen peroxide and catalyst. Efficiency of fuel is analyzed by studying various parameters: flash point, fire point, cloud point, pour point, kinematic viscosity, specific gravity and calorific value at different dosage of SnO2 (10, 20, 30 and 40 ppm). It is found that values of these parameters changes significantly by changing the dosage of catalyst.

Novel Colloidal Nanothermite Particles (MnO 2 /Al) for Advanced Highly Energetic Systems

Abstract: Nanothermites (metal oxide/metal) are tremendously exothermic and run with self sustaining oxygen content. Manganese oxide is one of the most effective oxidizers for nanothermite applications. This paper reports on the sustainable fabrication of different nanoscopic forms of colloidal manganese oxides including: MnO2 nanoparticles of 20 nm average particle size and Mn2O3 nanorods of 50 nm diameter and 1 µm length. TEM micrographs demonstrated mono-dispersed particles and rods. XRD diffractograms revealed highly crystalline materials. MnO2 nanoparticles (oxygen content 37 wt%) can offer high oxidizing ability compared with Mn2O3 nanorods (oxygen content 30 wt%). The integration of colloidal particles into energetic matrix can offer enhanced dispersion characteristics; consequently stoichiometric binary mixture of MnO2 and Al nanoparticles were re-dispersed in organic solvent. The integration of developed colloidal nanothermite particles into tri-nitro toluene offered enhanced shock wave strength by 35% using ballistic mortar test. Thanks to nanotechnology which offered sustainable manufacture and subsequent integration of one of the most effective nanothermite particles into highly energetic system.

Green Synthesis of Colloidal Copper Nanoparticles Capped with Tinospora cordifolia and Its Application in Catalytic Degradation in Textile Dye: An Ecologically Sound Approach

Abstract: Green synthesis has been considered as an ideal approach owing to its simplicity, cost effectiveness and minimal toxicity. Aim of the present study was to synthesize and characterize copper nanoparticle capped Tinospora cordifolia using green synthesis and further to evaluate its catalytic degradation property on different dyes. Various characterization parameters were performed such as particle size, PDI, zeta potential, microscopic study (SEM, TEM), interaction study through ATR-FTIR and DSC. Surface area of the sample was analyzed through the surface area analyzer. Catalytic degradation ability of synthesized nanoparticle was studied using various dyes such as reactive dye, direct dye, eosin yellowish and safranin.

Nanocomposite Bead (NCB) Based on Bio-polymer Alginate Caged Magnetic Graphene Oxide Synthesized for Adsorption and Preconcentration of Lead(II) and Copper(II) Ions from Urine, Saliva and Water Samples

Abstract: The present study describes the successful fabrication of bio-polymeric nanocomposite bead (NCB) of alginate caged magnetic graphene oxide (Alg-MGO). NCB was obtained by crosslinking of sodium alginate and calcium ions in the presence of MGO. Analytical techniques Fourier transform infra-red (FT-IR), field emission scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX) were used to characterize the Alg-MGO. Analytical application is conducted with magnetic solid phase extraction (MSPE) method for determination of Cu(II) and Pb(II) in urine, saliva and river water sample. The linear concentration range obtained were 0.33–25.00 µg L− 1 with appropriate coefficient of determination (R2 = 0.99) and low limit of detection (LOD = 0.21–0.71 µg L− 1, n = 3). The newly developed MSPE-NCB was successfully validated with standard reference material (SRM 2670a, NIST). Metal ions removal process was studied at high concentration level (1–200 mg L− 1) and isotherm models were applied. Langmuir isotherm is well fitted to experiments due to high value of coefficient of determination (R2) and proper adsorption capacity 96.13 and 103.09 mg g− 1 obtained for Cu(II) and Pb(II), respectively. Thermodynamic model is suggested spontaneous process, endothermic nature and physical sorption mechanism for uptake of selected metal ions from aqueous solution.

Dye Adsorption on Cubic Polyhedral Oligomeric Silsesquioxane-Based Poly(acrylamide-co-itaconic acid) Hybrid Nanocomposites: Kinetic, Thermodynamic and Isotherms Studies

Abstract: In the present study, poly(acrylamide-co-itaconic acid) hybrid nanocomposites were synthesized via free radical copolymerization method. Octavinyl polyhedral oligomeric silsesquioxane (OV-POSS) with different weight ratio (0, 4, 8, 12 and 14 wt%) was utilized as a cross-linker. Dye adsorption properties of the as-prepared hybrid nanocomposites were investigated for crystal violet (CV) elimination from aqueous solution. The effect of various parameters, such as OV-POSS content, adsorbent amount, pH, temperature, contact time and initial dye concentration, on the adsorption of CV was studied. Moreover, adsorption kinetic, isotherm and the thermodynamic of the CV adsorption on the so-called hybrid nanocomposites were studied.

Aquatic Biodegradation of Methylene Blue by Copper Oxide Nanoparticles Synthesized from Azadirachta indica Leaves Extract

Abstract: The toxicity of methylene blue (MB) dye is increasing gradually in the environment due to human activities which can be reduced more effectively by green synthesis along with nanotechnology. A nanomaterial, copper oxide nanoparticles (CuONPs), is synthesized using leaves extract of Azadirachta indica (Neem) at room temperature. Surface plasmon resonance of biosynthesized material at 232–236 nm clue the formation of NPs of CuONPs. The average size of NPs is found as 21.6 nm using atomic force microscopy. The face centered cubic structure of the CuONPs was analyzed using X-ray diffraction analysis. Biosynthesized NPs effectively degraded MB dye under different reaction conditions like time of contact between CuONPs and MB, dose of the CuONPs, exposure of UV light and temperature of the reaction mixture. The degradation process was optimized on above conditions for the maximum removal of MB dye in wastewater.