Search

We report ternary AgI–FG–TiO 2 nanocomposites prepared through fast microwave technique. In this study we introduced a novel chemical vapor deposition (CVD) approach to functionalize powder graphene oxide (GO). The functionalize graphene (FG) sheets were then used for the attachment of AgI and TiO 2 nanoparticles to form a ternary composites. The prepared composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopic analysis, X-ray diffraction (XRD), UV–vis absorbance spectra and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activity for hydrogen evolution was greatly affected by the introduction of FG and ternary component in the system.

In this study, a novel visible-light-responsive PbSe–TiO 2 nanocomposite photocatalysts were successfully synthesized through a facile sonochemical-assisted method, and characterized by XRD, SEM–EDX, TEM, and DRS to confirm its structure, morphology, composition, and optical property. In decolorization of rhodamine B, a significant enhancement in the reaction rate was observed with PbSe–TiO 2 composite, compared to the pure TiO 2 . The generation of reactive oxygen species was detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). The high photocatalytic activity can be attributed to the synergetic effect of PbSe nanoparticles and TiO 2 by extending the spectral response of TiO 2 to visible region and also help to reduce the charge recombination. Finally, the possible mechanism for generation of reactive oxygen species under visible light irradiation was proposed as well.

This study reports that the atmospheric pressure chemical vapor deposition (CVD) growth of large area graphene (LAG) over a Cu foil. The obtained large area graphene was further decorated with TiO2 nanoparticles via ultrasonic method. The surface structure, crystal phase, and elemental identification of these obtained LAG/TiO2 composite were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, and Raman spectra. The photocatalytic H2 evolution result illustrates Cu-LAG/TiO2 has been found to be a potential catalyst for conversion of solar energy to clean hydrogen energy under visible light-driven despite that the H2 evolution activity is not high enough in this stage.

Expanded graphene (EG) has been produced using fast oxidation/intercalation process. The as prepared EG were then used as conductive additive to study the electrochemical properties of activated carbon based electric double layered supercapacitors (EDLCs). The physiochemical properties of EG were studied using scanning electron microscopy, Raman spectroscopic techniques, atomic force microscopy and energy dispersive X-ray analysis. The electrochemical properties were studied using charge/discharge cyclic voltammetry and electrochemical impedance spectroscopy. All the electrochemical tests were carried out in 1 M, TEA BF4 in acetonitrile as a suitable electrolyte for our AC based supercapacitors. Electrochemical test reveals that EG greatly affect the conductivity of the ions through the AC/EG interface. The specific capacitance remains the same for smaller values of EG in the composites electrodes. These results also evident the optimum loading of graphene in the future graphene based EDLCs.

The as-synthesized graphene–MxSy (Sb2S3, MnS2, SnS) composites via a facile hydrothermal method efficiently catalyzed the photodegradation of methylene orange (MO) with high concentration in aqueous solutions under visible light irradiation. The generation of reactive oxygen species were detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). Based on the high photocatalytic activity, the graphene-SnS composite can be expected to be a practical visible light photocatalyst.

A visible-light photocatalyst containing Ag2Se and reduced graphene oxide (RGO) was synthesized by a facile sonochemical-assisted hydrothermal method. X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, and ultraviolet-visible diffuse reflectance spectroscopy results indicated that the RGO-Ag2Se nanocomposite contained small crystalline Ag2Se nanoparticles dispersed over graphene nanosheets and absorbed visible light. The high crystallinity of the nanoparticles increased photocatalytic activity by facilitating charge transport. N2 adsorption-desorption measurements revealed that the RGO-Ag2Se nanocomposite contained numerous pores with an average diameter of 9 nm, which should allow reactant molecules to readily access the Ag2Se nanoparticles. The RGO-Ag2Se nanocomposite exhibited higher photocatalytic activity than bulk Ag2Se nanoparticles to degrade organic pollutant rhodamine B and industrial dye Texbrite BA-L under visible-light irradiation (γ > 420 nm). The generation of reactive oxygen species in RGO-Ag2Se was evaluated through its ability to oxidize 1,5-diphenylcarbazide to 1,5-diphenylcarbazone. The small size of the Ag2Se nanoparticles in RGO-Ag2Se was related to the use of ultrasonication during their formation, revealing that this approach is attractive to form porous RGO-Ag2Se materials with high photocatalytic activity under visible light.

In this paper, a hybrid configuration of ant colony optimization (ACO) with artificial bee colony (ABC) algorithm called hybrid ACO–ABC algorithm is presented for optimal location and sizing of distributed energy resources (DERs) (i.e., gas turbine, fuel cell, and wind energy) on distribution systems. The proposed algorithm is a combined strategy based on the discrete (location optimization) and continuous (size optimization) structures to achieve advantages of the global and local search ability of ABC and ACO algorithms, respectively. Also, in the proposed algorithm, a multi-objective ABC is used to produce a set of non-dominated solutions which store in the external archive. The objectives consist of minimizing power losses, total emissions produced by substation and resources, total electrical energy cost, and improving the voltage stability. In order to investigate the impact of the uncertainty in the output of the wind energy and load demands, a probabilistic load flow is necessary. In this study, an efficient point estimate method (PEM) is employed to solve the optimization problem in a stochastic environment. The proposed algorithm is tested on the IEEE 33- and 69-bus distribution systems. The results demonstrate the potential and effectiveness of the proposed algorithm in comparison with those of other evolutionary optimization methods.

CoS2, CoS2–graphene and CoS2–graphene/TiO2 composite was synthesized by a facile sonochemical and hydrothermal method. X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, FT-IR, UV–vis and BET surface area was calculated by nitrogen adsorption were used. The FT-IR results illuminated that CoS2 and TiO2 band transfers electrons to graphene with functional groups attached. UV–vis patterns indicated that CoS2–graphene/TiO2 have good photoinduction effects in visible light region. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB), and industrial dyes such as Texbrite BA-L (TBA) under visible light.

Here we report a new composite material consisting of TiO2 nanoparticles grown in the presence of a layered PtSe2/graphene hybrid as a high-performance photocatalytic material. The heterogeneous PtSe2–graphene/TiO2 nanocomposites were successfully synthesized through a facile and fast microwave-assisted method. The prepared composites were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), Raman spectroscopic analysis, X-ray photoelectron spectroscopy (XPS), and UV-vis absorbance spectra and UV-vis diffuse reflectance spectra (DRS) analyses were obtained. The catalytic behavior was investigated through the decomposition of rhodamine B (Rh. B) as a standard dye and Texbrite MST-L as an industrial dye. This extraordinary photocatalytic activity arises from the positive synergetic effect between the PtSe2 and graphene components in this heterogeneous photocatalyst. In this study the graphene behaves as an electron transfer agent, collector, contributor and a source of active adsorption sites. The optical properties were also observed to be affected by the different weight% of graphene in the composites by observing their respective band gaps from DRS spectra.

Background: The endometrial thickness is an important determinant for the successful implantation and pregnancy. This research was aimed to evaluate relationship between the endometrial thickness with serum estradiol and progesterone levels in patients visited in Ob&Gyn clinic of Shahid Sadoughi hospital. Material and Methods: Enrolled in the study were 440 patients visited in Ob&Gyn clinic of Shahid Sadoughi hospital between Jan. 2011 to Sep. 2012. Only patients with regular menstrual cycle were included in study. Patients with myoma, adenomyosis, endometrial polyps or other uterine anomaly, those who smoked, women with BMI greater than 30 and who were taking medications that could affect endometrial thickness were excluded. Endometrial thickness one day before and 5-7 days after ovulation was measured by using trans-vaginal ultrasonography. Also, serum estradiol and progesterone levels were measured in 5-7 days after ovulation. Data analysis was done through SPSS version 16 with using descriptive statistics and ANOVA. Results: The mean age of patients was 27.37±4.44. Endometrial thicknesses were 9.80±0.80 and 10.13±1. one day before and 5-7 days after ovulution, respectively. 5% of patients had thin endometrium (

A heterogeneous material consisting of a tube type TiO2 was grown in the presence of a CoSe2/graphene hybrid, as a high-performance photocatalyst material, through a fast microwave-assisted technique. The prepared composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopic analysis, UV-vis absorbance spectra and UV-vis diffuse reflectance spectra (DRS) analysis. The hydrogen evolution rate for ternary composites was found to be markedly high compared to bare TiO2 and binary CoSe2/graphene composites. This extraordinary photocatalytic activity for hydrogen evolution arises from the positive synergistic effect between the CoSe2 and graphene components in our heterogeneous system. The optical properties were also found to be affected by the different weight% of graphene in the composites by observing their respective band gaps from the DRS spectra.

Nanostructured ZnSe-graphene/TiO 2 was synthesized by a hydrothermal-assisted approach. ZnSe-graphene/TiO 2 exhibited favorable adsorption of rhodamine B, a wide wavelength absorption range, and efficient charge separation. Reactive oxygen species were generated by the oxidation of 1,5-diphenyl carbazide to 1,5-diphenyl carbazone. The sonocatalytic reaction mechanism was proposed. These findings potentially broaden the applications of sonocatalytic technologies.

CoS 2 and a CoS 2 –graphene composite were synthesized via a facile sonochemical and hydrothermal method. As-prepared samples were characterized by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray analysis, transmission electron microscopy, and UV-vis diffuse reflectance spectroscopy. The CoS 2 –graphene composites exhibited high dye adsorption, extended light absorption, and efficient charge separation properties. Hence, for photodegradation of methylene blue (MB), significant enhancement of the reaction rate was observed for CoS 2 –graphene compared to pure CoS 2 . The high activity can be attributed to positive synergetic effects between CoS 2 and graphene. The excellent photoinduced charge separation and observed red shift make these hybrid materials potential candidates for the development of high-performance next-generation photocatalyst materials.

The authors report novel material PbSe/graphene nanocomposite synthesis via facile ultrasonic assisted method. The structural and physicochemical properties of PbSe/graphene composite are further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with an energy-dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), and Raman spectroscopy analysis. The photocatalytic activities were investigated by the degradation of methylene blue and rhodamine B as a standard dye. This study suggests that the as-prepared PbSe/graphene nanocomposite can be utilized as an efficient photocatalyst material.

Cadmium selenide (CdSe)-graphene composite materials were synthesized via a facile hydrothermal method and the intriguing catalytic activity of the composites was investigated using organic dyes in complete absence of irradiation source (UV or visible light). The catalytic activity of CdSe-graphene composites was measured using methyl orange (MO) and rhodamine B (Rh.B) dye solutions. The characterizations of composites were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and with energy dispersive X-ray (EDX). The catalytic degradation was measured by analyzing the decrease in absorbance spectra in UV-Vis spectroscopy. The degradation of the organic dyes in absence of any irradiation was illustrated by the degradation property of CdSe and charge mobility. The catalytic activity after repeated use of the composites was also tested in order to investigate the stability of CdSe-graphene composites.

MWCNT-TiO2 and Pd-MWCNT/TiO2 composites were prepared by a high-intensity ultrasonic method using a lower temperature (80oC), and their high photocatalytic activity was evaluated by the degradation of reactive black B solutions (RBB) under visible light. The surface structure, crystal phase, and elemental identification of these composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, and UV–vis absorption spectra (UV–vis), respectively. The degradation of RBB solution was determined using UV–vis spectrophotometry. An increase in photocatalytic activity was observed and it may attribute to increase of the photo-absorption effect by the multi-walled carbon nanotubes (MWCNT) and the cooperative effect of the Pd element.

We report a simple and effective route to synthesize graphene based platinium selenide nanocomposites by facile and fast microwave assisted techniques. The “as-prepared” composites are further characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), Raman spectroscopic analysis, UV–vis absorbance spectra analysis and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activities were investigated by the degradation of methylene blue and rhudamine B as standard dye. This result gives a promising development towards graphene based efficient photocatalyst that employed visible light as an energy source.

In the present work, powders with different relative mole ratios of WO 3 -fullerene/TiO 2 were irradiated by visible light and ultrasonic. The composite obtained was characterized by BET surface area measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), fourier transform infrared (FT-IR), transmission electron microscopy (TEM) and UV–vis analysis. A methylene blue (MB) solution under visible light and ultrasonic irradiation was used to determine the catalytic activity. The generation of reactive oxygen species were detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). Finally, we performed experiments to find the optimum relative mole ratio of fullerene for the degradation of MB.

ZnS and ZnS/TiO 2 were prepared by chemical deposition. The prepared photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and transmission electron microscopy (TEM). The generation of reactive oxygen species was detected by monitoring the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). Excellent catalytic degradation of methylene blue (MB) solution was observed using the ZnS/TiO 2 composites during irradiation with visible light. The results show that the photocatalytic performance of TiO 2 nanoparticles is improved by loading with ZnS.

A novel composite, CdSe-graphene, was synthesized using facile hydrothermal method. The structural characteristics studies of the synthesized composites were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), Brunauer, Emmett, Teller specific surface area (BET) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was investigated by the degradation of methylene blue as standard dye. The degradation of MB was calculated based on the decrease in concentration of the dye with respect to regular time intervals. The reusability tests were done to investigate the stability of the used catalysts. Additionally the antibacterial activity of CdSe-graphene was also investigated using bacterium Streptococcus aureus ( S. aureus ).

Activated carbon fiber (ACF) was modified with MnS nanoparticles to prepare MnS-ACF, and it was employed for preparation of MnS-ACF/TiO₂ composites with titanium (IV) n-butoxide (TNB). The properties of MnS-ACF/TiO₂ composites were characterized by XRD, SEM, and EDX. EDX results showed the presence of C, O, and Ti as major elements and traces of the metal elements Mn and S. The photocatlytic activity was evaluated by degradation of methyl blue (MB) and methyl orange (MO) dye. The results demonstrated that as-prepared samples could effectively photodegrade MB and MO under UV irradiation. Subsequently, the decomposition of MB solution showed the combined effects of adsorptions by ACF and enhanced photocatalytic effect by TiO₂. Finally, the photocatalytic effect increased due to photo-induced-electron absorption effect by ACF and electron trap effect by comodified MnS nanoparticles.

This paper introduces a microwave-assisted synthesis method to prepare hybrid Bi₂Se₃-GR/TiO₂ nanocomposites, which exhibit superior properties over single component materials. The as-prepared composites were characterized by XRD, UV-vis absorbance spectra, SEM,TEM, EDX, and BET analyses, revealing uniform covering of the graphene nanosheet with Bi₂Se₃ and TiO₂ nanocrystals. For visible light photocatalysis of Rh.B, a significant enhancement in the reaction rate was consequently observed with Bi₂Se₃-GR/TiO₂ composites. The degradation rate(kapp) obtained for sonophotocatalysis was 6.8× 10-3 min-1, roughly 2.2 times better than that of VL photocatalysis under higher concentrations of Rh.B. The sonophotocatalysis was faster due to greater formation of reactive radicals as well as an increase of the active surface area of the Bi₂Se₃-GR/TiO₂ composites. The high activity is attributed to the synergetic effects of high charge mobility and red shift of the absorption edge of Bi₂Se₃-GR/TiO₂.

In this study novel material PbS–graphene/TiO2 composites were prepared by sol–gel method. The “as-prepared” composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) with an energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS) and Raman spectroscopic analysis. The photocatalytic activities were investigated by the degradation of methylene blue (MB) as a standard dye. We observed that coupling of PbS with TiO2 extends the photoresponse to visible region. This revealed that the excellent photoinduced charge separation abilities and transport properties of graphene make these hybrids as potential candidates for developing high-performance next-generation devices.