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An idea of employing an iron-assisted carbon (FeC) monolayer for delivery of 2-thiouracil (2TU) was examined in this work by analyzing structural features for singular and bimolecular models. Density functional theory (DFT) calculations were performed for optimizing the structures and evaluating molecular and atomic descriptors for analyzing the models systems. Two bimolecular models were obtained assigning by S-FeC and O-FeC models, in which each of S and O atom of 2TU was relaxed towards the Fe region of FeC surface in the mentioned models, respectively. The results indicated that both models were achievable with slightly more favorability for formation of S-FeC model. The obtained molecular orbital properties revealed the dominant role of FeC monolayer for managing future interactions of attached 2TU, which is indeed a major role for employing nanomaterials for targeted drug delivery purposes. In addition to energies and molecular orbital features, atomic quadrupole coupling constants indicated the benefit of employing FeC monolayer for drug delivery of 2TU.

Polyaniline PANI/(SrFe12O19)(1-x)/(Co0.8Ni0.2Fe2O4)(x) (x = 0.2, 0.4, 0.6, 0.8) composites were prepared via the in situ polymerization process. The structure, morphology and electromagnetic absorption properties of samples were studied. XRD (x-ray diffractometer), FESEM (field emission scanning electron microscopy), and FTIR (field transform infrared) analyses demonstrated that SrFe12O19/Zn0.4Co0.2Ni0.4Fe2O4 ferrite particles were covered by PANI coating. VSM measurement revealed by adding non-magnetic polymer (PANI), magnetic features of aimed composites declined. The electromagnetic absorption of synthesized samples was measured by VNA. In the frequency range of 8.2–12.4 GHz (X-Band), the reflection loss improved to − 28.5 dB from − 2.93 dB composites of PANI/(SrFe12O19)0.2/(Zn0.4Co0.2Ni0.4Fe2O4)0.8 in comparison to (SrFe12O19)0.2/(Zn0.4Co0.2Ni0.4Fe2O4)0.8. Due to the perfect impedance matching between PANI as the dielectric part, and ferrites in the case of the magnetic part, the reflection loss decreased in PANI/(SrFe12O19)(1-x)/(Co0.8Ni0.2Fe2O4)(x) composites. The minimum reflection loss of the PANI/SrFe12O19/Zn0.4Co0.2Ni0.4Fe2O4 composites was − 28.6 dB at the frequency of 11.5 GHz.

Ce-substituted strontium hexagonal M-type SrCexFe12-xO19 ferrites (x = 0.0, 0.03, 0.05, 0.07, and 0.1) and various concentrations of poly(N-vinilpyrrolidone) (PVP) polymer were prepared by citrate ...

N,F-TiO2 and SiO2 nanoparticles have been synthesized by a sol–gel method and grown on reduced graphene oxide by a solvothermal method at different molar ratios. The microstructure and morphology of the N,F-TiO2/SiO2/rGO nanocomposite were investigated by Fourier-transform infrared spectroscopy, x-ray diffraction analysis, field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray spectroscopy, and Brunauer–Emmett–Teller surface area (SBET) measurements. The synthesized nanocomposite was used for photocatalytic degradation of Methyl Red (MR) dye. Ultraviolet–visible (UV–Vis) spectrophotometry was used to determine the degree of dye degradation before and after contact with the nanocomposite, and the absorbance was measured at 518 nm. The results confirmed that the N,F-TiO2/SiO2/rGO nanocomposite degraded 95% of MR after 60 min under visible-light irradiation. Factors affecting its photocatalytic ability were investigated and optimized. The results showed that the highest degradation efficiency was observed when 1.5 mL silica sol was used to synthesize the nanocomposite. Finally, the mechanism of Methyl Red degradation was investigated.

Purpose This paper aims to introduce constructed CeO2/TiO2 core/shell nanoparticle as sensitive substance organic compounds. Design/methodology/approach The CeO2 nanoparticles were synthesized by hydrothermal treatment. Then CeO2/TiO2 core/shell was fabricated by sol–gel method preparation of TiO2 in the presence of ceria nanoparticles and applied as the sensitive material to make a sensor. Findings Formation of the nanoparticles was confirmed by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). The synthesized sensor exhibited not only good sensitivity to volatile organic compounds at room temperature but also logarithm of sensitivity versus concentrations was linear. Research limitations/implications The sensor shows acceptable sensitivity to volatile organic compound at room temperature. Practical implications Experimental data revealed satisfactory reproducibility and short response and recovery times. Originality/value A radical mechanism for gas sensor reaction in two pathways was considered and activation energies were calculated by density functional theory (DFT) method to describe different sensitivities of tested volatile gases. The experimental results were consistent with the calculations.

SrFe12O19/Zn0.4Co0.2Ni0.4Fe2O4 hard/soft ferrite composite particles with 20, 40, 60 and 80 wt.% of soft phase were prepared by one-pot sol-gel auto-combustion and physical mixing methods. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and vibrating sample magnetometer (VSM) were used to characterize the structural and magnetic properties of the samples. XRD spectrum revealed the formation of mixed ferrite phases in the composite particles. The hysteresis loops of the samples showed the presence of exchange coupling between the hard and soft ferrites. The composite particles with 20 and 60 wt.% of the soft phase demonstrated the highest Mr/Ms ratio, i.e. 0.29 and 0.28, respectively. In addition, the highest Ms, Mr and Hc were achieved in the composite particles with 40, 60 and 20 wt.% of the soft phase, respectively. Compared to the physical mixing method (PM), the composite particles prepared by the sol-gel auto-combustion method (OP) demonstrated better magnetic properties. The exchange coupling interaction between the hard and soft ferrite phases was similar in both methods. These composite particles exhibited magnetically single phase behaviour, however, the saturation magnetization was lower in the physical mixing pared to that of the one-pot method.

In this research, the Staudenmaier method adopted to synthesize the reduced graphene oxide to be used in the ZnO@SiO2/rGO nanocomposite preparation by sol-gel assisted hydrothermal method. SEM images showed the formation of graphene oxide layers with a thickness of about 41 ± 1 nm as well as the formation of spherical ZnO@SiO2 nanoparticles with an average diameter of 32 ± 1 nm on graphene plates. The formation of expected elements in the fabricated nanocomposite, confirmed by the EDS analysis. XRD patterns showed that rGO and ZnO were crystalline and SiO2 was non-crystalline. The FT-IR spectrum of the desired microstructure and the TEM image confirmed the core/shell structure. The application of this nanocomposite as a gas sensor was evaluated. According to the measurements done at the ambient conditions (RH 45%, 29 °C), the sensor sensitivity to 300 ppm of the ethanol, methanol and 1-propanol, were 131.7, 21.8 and 156.8 units, respectively. Although the logarithm of the sensitivity linearly depends on the concentration of the samples in the range of 150–450 ppm, but the maximum R2 of 0.9478 indicates the ability of this sensor to quantitatively measure 1-propanol. The RSD percentage less than five for all samples indicates good reproducibility of the sensor response. Ten months investigation revealed that the appropriate time for repetitive responses of synthesized sensor is about 8 months. The response and recovery times were measured as improved sensor properties. The results showed that the synthesized sensor can be used as a quantitative and qualitative measurement of 1-propanol. Finally the sensing mechanism was discussed based on electronic transmissions.

In order to investigate the effect of hydroxypropyl cellulose (HPC), polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) on adsorbing capacity of nanosorbent Nd-TiO2/GO, Nd-TiO2/HPC/GO, Nd-TiO2/PVP/GO and Nd-TiO2/PEG/GO nanocomposites were synthesized. Studies by Fourier transform infrared spectroscopy confirmed the expected structure and X-ray diffraction results confirmed the formation of crystalline phase of anatase titania and also graphene oxide (GO). Scanning electron microscopy pictures and energy dispersive X-ray spectroscopy analysis showed the formation of Nd-TiO2 nanoparticles. These nanocomposites were used for removal of lead(II) and copper(II) from water and the effective factors on removal were optimized. The results showed that the maximum removal for all three nanocomposites was at pH = 7. The amount of adsorbent and contact time for Nd-TiO2/HPC/GO and Nd-TiO2/PVP/GO nanocomposites was equal to 0.02 g and 20 minutes respectively, but they were equal to 0.01 g and 15 minutes for Nd-TiO2/PEG/GO nanocomposite. Investigating the effect of interfering ions showed they had no considerable effect on removal efficiency. In order to investigate the effect of photocatalytic activity in optimal conditions and in the presence of visible–ultraviolet light, the removal process was performed. The results showed an increase in removal efficiency. Furthermore, the ability of synthesized nanosorbents to decompose organic compounds available in water was confirmed and their energy band gaps were calculated.

The Ce O 2 /Ti O 2 core/shell nanostructures were successfully synthesized by sol-gel assisted hydrothermal method and doped by Z r 4+ and V 3+ ions. Different characterization experiments used to identify particles morphology and microstructures to confirm the formation of desired core/shell structure. The produced materials were used to make gas sensors for volatile organic compounds. Doping the core/shell structure by 1% molar ratios of zirconium (IV) and vanadium (III) increased its sensitivity from 26.50 to 277.50 with respect to 420 ppm ethanol at room temperature (29 °C, 45 % RH). Linear dependence of the sensitivity logarithm to the concentration of volatile organic compounds with reasonably low relative standard deviation (%RSD) suggests that the sensors can be used for quantitative and qualitative measurements. Long time measurements of the sensitivity revealed that the sensors output are temporally stable up to 11 months. The sensitivity mechanism is explained based on the depletion region created in the hetero-junction of semiconductor materials.

In order to investigate the effect of hydroxypropyl cellulose (HPC), polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) on adsorbing capacity of nanosorbent Nd-TiO

Cerium oxide nanoparticles (CeO2NPs) exhibit biomedical properties as well as cytotoxic effects on tumor cells. Therefore, recent CeO2NPs have been regarded by numerous researchers as metal-based antitumor agents. Moreover, a new series of CeO2NPs having different structures and morphologies such as nickel (Ni)-doped CeO2, hollow CeO2 (hCeO2), and hollow CeO2/silicon dioxide (SiO2) (hCeO2/SiO2) NPs have been synthesized. All these compounds have been further characterized by fourier transform infrared (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX), high-resolution transmission electron microscopy (HRTEM), and Brunauer-Emmett-Teller (BET) analyses. Similarly, HRTEM analyses showed that hCeO2/SiO2 nanostructures were composed of CeO2 as core and SiO2 as shell. To this end, cytotoxic activity of synthesized NPs was investigated on HT-29, as a human colorectal cancer cell line and human foreskin fibroblast cell line (HFFF2). The hollow core/shell nanostructures indicated more cytotoxicity compared with other synthesized compounds on HT-29 cell line. The results also revealed that hCeO2/SiO2NPs had less half maximal inhibitory concentration (IC50) (18.625 µg/ml) than other synthesized compounds. All four compounds showed significantly less cytotoxicity effect in non-cancerous cells (HFFF2) compared to tumoral cells (HT-29).

A novel Nd, Zr–TiO2/SiO2 nanocomposite thin film was successfully prepared with various amounts of Nd3+ and Zr4+ as codopant ions for self-cleaning applications. In the first step, two types of Zr, Nd–TiO2/SiO2 thin films were prepared using ZrCl4 and ZrOCl2 compounds as a source of second doping agent ions. The result of the scanning electron microscopy (SEM) indicated that ZrOCl2 precursor produces a more monotonous thin film, but study of the photocatalytic activity of these thin films showed that ZrCl4-based thin film possess a more significant photocatalytic activity. Based on these results, ZrCl4 was chosen as a source of doping ion. Two kinds of Nd, Zr–TiO2/SiO2 nanocomposite thin films A and B were synthesized using various techniques. Type A thin film was coated on a glass substrate by heat treatment, but Type B was coated on polycarbonate sheets without any heat treatment process. The SEM images and XRD pattern showed that the optimum amount of doping ion in relation to Ti3+ is 0.1 %. In this circumstance, the most monotony of film was seen and the main formed phase was anatase. The sample structures were characterized by infrared spectroscopy. The nanocomposite films were found to be active for photocatalytic decomposition of methyl orange as an organic pollutant.

A novel Cu–TiO2/chitosan hybrid thin film was successfully prepared without any heat treatment process by sol–gel method on a polycarbonate substrate. Based on the photocatalytic activity and adsorption property of the entire thin film, a simple, reliable, reproducible and inexpensive method was developed for the removal of some heavy metals from aquatic media. The removal process of Pb2+ and Cr6+ was performed by flotation of coated polycarbonate substrate in the bulk of sample for a definite time in absence and presence of light. The effect of influential parameters in removal process, including thin film surface area, removal time, sample volume and pH was investigated and variation in selected ion concentrations was monitored using a graphite furnace-atomic absorption spectrometer. Considering the optimized conditions, effect of interference ions was studied and according relative standard deviation amounts, no evidence of interference was observed. The proposed method showed good reproducibility in a way that the amounts of relative standard deviation percentage values (n = 10) for Pb2+ and Cr6+ were obtained 4.303 and 3.865, respectively. The whole procedure showed to be conveniently applicable and quite easy to manipulate.