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In this work fullerene (C60) was noncovalently doped to zinc–aluminum layered double hydroxide/polyvinyl alcohol (ZnAl–LDH/PVA) nanocomposites and the obtained samples were used for the photodegradation of methylene blue and congo red dyes from water solution. The structural, optical properties, surface morphology, specific surface area and chemical composition of C60 doped LDH were characterized by XRD, UV–Vis, PL, SEM, TEM and BET technique. The average crystallite size is increased from 8 to ~ 20 nm, and the dislocation density (δ) decreased from 0.0127 to ~ 0.003 nm2 by the increasing the amount of C60 doping 1% to 10%, 20% and 60%. Fullerene was used as a dopant and support material to improve the photocatalytic activity of LDH. The photodegradation parameters were determined with 1%, 10%, 20% and 60%wt of C60 doped LDH under visible-light. A complete photodegradation of MB (PD% = ~ 99%) on the nanocomposites occurred during 10 h irradiation The photodegradation rate constant (kapp) is 0.024 min−1 for CR onto 1% C60 doped ZnAl–LDH/PVA. The results show that noncovalent doped C60 into ZnAl–LDH/PVA matrix reduces the recombination of electron–hole pairs and increases the efficiency of the photocatalyst. [ABSTRACT FROM AUTHOR]

The frequency and temperature dependences of the tangent of dielectric loss angle as well as the real and imaginary part of the dielectric constant of MnGaInTe4 crystals are investigated in the frequency range of 10² to 106 Hz. The experimental values of the studied characteristics are determined. The real and imaginary parts of the permittivity are found to undergo significant dispersion, which has a relaxation nature. The main type of dielectric losses in MnGaInTe4 crystals in the frequency range of 10² to 106 Hz are the electrical conductivity losses. The conductivity is characterized by a zone-hopping mechanism. The activation energies of charge carriers are determined. [ABSTRACT FROM AUTHOR]

In the present investigation, pure and different concentrations (2%, 4%, 6%, 10%) of Ag-doped Co3O4 nanoparticles have been synthesized by the sonochemical method and subsequent calcination at different high temperatures. Structural, optical, morphological properties and elemental composition of synthesized nanoparticles have been characterized using X-ray diffraction, UV–visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. According to X-ray diffraction results, no peaks related to silver or silver oxide were observed in the diffractograms of doped samples. Blue shift was observed in the absorption curve of Ag-doped Co3O4 nanoparticles compared to undoped Co3O4 nanoparticles. From transmission electron microscopy measurements, 2%, 4% and 6% Ag-doped Co3O4 nanoparticles thermal annealed at 500 °C exhibit sphere-like and irregularly structured morphology, while 10% Ag-doped Co3O4 nanoparticles have a rhombohedral-like, hexagonal and spherical morphology. The dielectric constant value (ɛʹ) was found to decrease with increasing frequency and it can be explained by Maxwell–Wagner model. The value of the dielectric constant increased with increasing of temperature from 25 to 100 °C and the highest value was observed for Ag0.1Co2.9O4/PVA sample at 100 °C temperature. [ABSTRACT FROM AUTHOR]

This research concentrates on enhancing TENGs via nylon/TiO2 nanocomposites. The integration of TiO2 nanoparticles into nylon enhances triboelectric characteristics, promoting charge transfer during mechanical deformation. Experiments demonstrate that introducing TiO2 nanoparticles to nylon by a simple spray coating method enhances dielectric permeability, favorably impacting TENG's performance. A TENG with nylon and polysiloxane layers initially achieved 30.36 V in open-circuit voltage and 1.82 μA in short-circuit current. The introduction of TiO2 nanoparticles significantly improved performance, reaching peak values of 41.38 V and 2.5 μA after 15 spray-coating cycles. Nonetheless, excessive TiO2 incorporation diminished TENG performance by reducing the active contact area between nylon and polysiloxane layers. [ABSTRACT FROM AUTHOR]

In this paper we present the results of studies into the frequency and temperature dependences of the dielectric loss tangent and the real and imaginary parts of the permittivity in MnGaInSe4 single crystals in an alternating electric field. The main type of dielectric losses in MnGaInSe4 single crystals in the frequency range of 8 × 103–3 × 105 Hz is established to be electrical conductivity losses, while the conductivity is characterized by the zone-hopping mechanism. The activation energies of current carriers of single crystals are determined. The real and imaginary parts of the permittivity are found to undergo significant dispersion, which is of a relaxation nature. [ABSTRACT FROM AUTHOR]

A new type of Ag2S-CdS/Ag/GNP nanocomposite material was successfully synthesized in the presented work. The structural and physical properties of compounds were studied separately and together. Ag2S-CdS/Ag/GNP nanocomposite materials were studied by Xray diffraction (XRD), Ultraviolet-Visible (UV-Vis), Fourier Transform Infrared (FTIR), Raman spectroscopy and Scanning Electron Microscopy (SEM). Based on the results, Ag nanowires (NWs) were successfully synthesized, and then it was determined that during the hybridization process, two phases of acanthite Ag2S and the cubic crystal system of Ag2O were formed. Then, Ag2S-CdS NWs were formed from mixed monoclinic Ag2S and hexagonal CdS. In the absorption spectrum of Ag NWs, the main absorbance peaks were observed at 357.3 nm and 380.2 nm. The energy gap (Eg) values of the Ag sample are 3.8 eV. The band gap value of Ag2S (2.5, 3.8, 4.6 eV) and Ag2S-CdS (2.5, 3.8, 4.8 eV) have a triple value due to the formation of a hybrid structure. The Raman spectrum of Ag2S-CdS belongs to longitudinal-optical (LO) phonon modes of zinc-blende phase CdS and for the 1, 2, and 3 times spin-coated samples on the surface of GNP/PVA have observed all characteristic Raman peaks, which belong to NWs at 485.13 cm-1, and 960.22 cm-1. [ABSTRACT FROM AUTHOR]

The frequency spectra and temperature dependences of the ac electric conductivity of MnGa2S4 single crystals have been studied. It is established that the conductivity increases with the frequency and exhibits a resonance at 435–500 kHz. The activation energies of current carriers are determined. The activation energy exhibits a frequency dependence, which is related to a decrease in the relaxation time of blocking barrier layers with increasing frequency. [ABSTRACT FROM AUTHOR]

The frequency and temperature dependences of the permittivity and conductivity of FeGaInS4 single crystals in an ac current have been investigated. The permittivities of single crystals and activation energies of permittivity and conductivity are determined. It is established that the conduction of these crystals in the temperature range under study has an activation nature. A frequency dependence of the activation energy is observed, which is related to the decrease in the relaxation time of blocking layers with an increase in frequency. [ABSTRACT FROM AUTHOR]

Results of investigations of temperature and frequency dependences of the permittivity and conductivity of FeIn2Se4 layered single crystals on alternating current are presented. The permittivity of single crystals and the activation energies of charge carriers are determined. In the temperature range under investigation, the conductivity is caused by the activation mechanism. [ABSTRACT FROM AUTHOR]

The temperature dependence of electrical conductivity and current-voltage characteristics of FeIn[sub 2]Se[sub 4] single crystals were studied. It is shown that the current in the nonlinear range of the current-voltage characteristic is caused by the field effect. The activation energy of charge carriers, the concentration of traps, and the shape of a potential well in the region of a trap are determined. [ABSTRACT FROM AUTHOR]

The temperature dependence of conductivity and current–voltage characteristics of MnIn2Se4 crystals have been studied. It is shown that the current in the nonlinear part of the current–voltage characteristic is due to the field effect. The activation energies of carriers and trap concentrations are determined. A relaxation of current with time is observed in MnIn2Se4. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

We have prepared cobalt sulfide (CoxSy) nanoparticles through a successive ionic layer adsorption and reaction (SILAR) method at room temperature. Co(NO3)2 ? 6H2O aqueous solution was used as a cobalt precursor, Na2S ? 9H2O and thiourea [(NH2)2CS] aqueous solutions were used as sulfur precursors. Functionalized nitrile butadiene rubber (FNBR) was used as a stabilizing agent for the formation of nanoparticles and contains -PO(OH)2 and -(O)PO(OH)2 acid groups. Obtained CoxSy/FNBR nanocomposites were annealed at 100°C in a vacuum for 6 h. The prepared nanocomposites were characterized by XRD, SEM, EDX, UV-Vis and FT-IR spectrometer. In case thiourea is used as asulfur source, mixed phases of Co3S4, CoS1.097 and CoS2 were obtained with the dominance of Co3S4 phase. A possible formation mechanism, physical and chemical stabilization into the functional polymer matrix (FNBR) for the growth processes have been discussed. [ABSTRACT FROM AUTHOR]

Organic-inorganic nanocomposites of polyvinyl alcohol (PVA) and CuS nanoparticles were prepared utilizing a combination of successive ionic layer adsorption and reaction (SILAR) and ion exchange processes. Initially, CdS particles were prepared that were imbedded in PVA matrix. The Cd in these nanocomposites was ion exchanged with Cu in a CuSO4 solution. Samples in each stage of synthesis were analysed by XRD for crystal structure, SEM for cros-sectional morphology, EDX for elemental distribution, UV-Vis for band gap measurement and XPS for the chemical structure. CdS/PVA nanocomposites conveniently transforms to CuS/ PVA during the ion exchange process producing nanocomposite showing only minor residual CdS. [ABSTRACT FROM AUTHOR]

In the present investigation, Cu x Co 3- x O 4 ( x = 0, 0.02, 0.04, 0.06, 0.1) nanoparticles have been synthesized by the sonochemical method and subsequent calcination at high temperature. The synthesized nanoparticles were further characterized using X-ray diffraction, UV-vis spectroscopy, FT-IR spectroscopy, Raman spectroscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The analysis results showed that nanoparticle size, band gap and photocatalytic activity of Cu x Co 3- x O 4 compounds change by altering the Cu doping content. According to the XRD study, no impurity peaks associated with copper or copper oxide phases were observed in the diffractograms of doped samples. The highest degradation of methylene blue dye under visible light was observed in the presence of Cu 0.02 Co 2.98 O 4 nanoparticles and found to be 87.51% after 330 minutes. This value increased with increasing the amount of photocatalyst and with decreasing dye concentration., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)