Ghader Hosseinzadeh
Abstract
In the current work, a novel ZnO-Cu2O heterojunction was synthesized from ZnO nanorods and Cu2O nanoparticles via hydrothermal route and was applied for the first time as a visible light active photocatalyst for decomposition of Paraoxon insecticide. Crystallinity, shape and size of particles, and optical ...
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In the current work, a novel ZnO-Cu2O heterojunction was synthesized from ZnO nanorods and Cu2O nanoparticles via hydrothermal route and was applied for the first time as a visible light active photocatalyst for decomposition of Paraoxon insecticide. Crystallinity, shape and size of particles, and optical properties of the synthesized heterojunction nanocomposites were evaluated by XRD, FESEM, EDS, Mott-Schottky, photocurrent analysis and UV-Visible spectroscopy analyses. Based on the obtained results the ZnO-Cu2O heterojunction nanocomposite was successfully synthesized and compared to pure ZnO semiconductor has the enhanced photocatalytic efficiency. The nanocomposite with 40% weight percentage of Cu2O has the best photocatalytical activity of 0.0201 min-1, which could be related to the improvement of optical properties (increasing of the visible light harvesting ability) and the reduction of the recombination of the photoinduced electron-hole pairs. In addition, according to the radical trapping tests and Mott-Schottky experiments, superoxide radical was determined as the main oxidizing species for photocatalytic degradation of Paraoxon, and a type II charge transfer process was proposed for the improved photocatalytic activity.
PARMESHWAR LAL MEENA; Ajay Kumar Surela; Krishna Poswal
Abstract
Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%), nanocomposites using simple precipitation method with variation of CuO content and the activities of prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye ...
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Here in the present study, we report the synthesis of ZnO nanoparticles, ZnO/CuO(3%), ZnO/CuO(5%), and ZnO/CuO(10%), nanocomposites using simple precipitation method with variation of CuO content and the activities of prepared samples were investigated for degradation of Brilliant Cresyl Blue (BCB) dye under visible light conditions in aqueous solutions. The structural, morphology, optical and compositional characteristics of fabricated samples were characterized by using Fourier Transform Infra-Red (FTIR) Spectroscopy, Field Emission Scanning Electron Microscopy combine electron dispersive spectroscopy (FESEM-EDS) and UV-vis spectroscopy. FESEM images show that ZnO nanoparticles are polygon like shape structure while ZnO/CuO have polygon and sheet shape structures. XRD patterns reflect the high crystalinity and purity of samples. The optical band gap values determined from optical absorption method indicate that band gap energy decreased with increase of CuO content in ZnO. The catalytic efficiency of the ZnO/CuO hybrid nanocomposite was observed to be higher than the ZnO nanoparticles under similar reaction conditions, 97.30% of Brilliant Cresyl Blue (BCB) dye was degraded after 100 min of irradiation of visible light radiation using the ZnO/CuO(5%) hybrid nanocomposite. The higher efficiency of ZnO/CuO compare to ZnO may be due to increased surface area and decreased band gap energy. The kinetic study of the photoctalytic degradation displayed that hybrid ZnO/CuO degrdaded dye with high rate constant k (34.88x10-3 min -1) compare to ZnO (k, 7.00x10-3 min-1). The optimization of reaction conditions of photodegradation process were attained by the variation in reaction factors such as pH, dye concentration, catalyst amount, and reaction time.
Atefeh Tizchang; Yoones Jafarzadeh; Reza Yegani; Elham Shokri
Abstract
In this study, polysulfone (PSf) nanocomposite membranes embedded with functionalized nanodiamond (ND) were prepared via Non-Solvent Induced Phase Separation (NIPS) method. ND nanoparticles were silanized by using the esterification reaction of hydrolyzed vinyltrimethoxysilane (VTS) in alcoholic solution ...
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In this study, polysulfone (PSf) nanocomposite membranes embedded with functionalized nanodiamond (ND) were prepared via Non-Solvent Induced Phase Separation (NIPS) method. ND nanoparticles were silanized by using the esterification reaction of hydrolyzed vinyltrimethoxysilane (VTS) in alcoholic solution in order to enhance the compatibility between ND and PSf. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed that ND nanoparticles were successfully functionalized by silane groups. Nanocomposite membranes were then prepared with different percentages of silanized NDs (SNDs). The membranes were characterized using a set of analyses and the results showed that the addition of SNDs up to 1.0 wt.% resulted in an increase in hydrophilicity, water content, porosity and water flux of membranes. Moreover, Scanning Electron Microscopy (SEM) images indicated that the membrane with 1.0 wt. % nanoparticles had more pores on the membrane surface with smaller average pore size in comparison to other membranes. Antifouling properties of the membrane was also investigated in filtration of humic acid solution and the results showed that reversible fouling and flux recovery of membranes increased at the presence of SNDs.
Syarifah Nazirah Wan Ikhsan; Norhaniza Yusof; Farhana Aziz; Nurasyikin Misdan; Ahmad Fauzi Ismail
Abstract
Halloysite nanotube/ferrihydrite (HNT/HFO) nanocomposites have been synthesized using a simple chemical precipitation method using only one-pot method. The synthesized nanocomposites were characterized for its physicochemical as well as morphological characteristics through X-Ray Diffraction (XRD), Fourier ...
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Halloysite nanotube/ferrihydrite (HNT/HFO) nanocomposites have been synthesized using a simple chemical precipitation method using only one-pot method. The synthesized nanocomposites were characterized for its physicochemical as well as morphological characteristics through X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Transmission Emission Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDX) as well as Brunauer–Emmett–Teller (BET). The morphology of the synthesized nanocomposites revealed the attachment of HFO to the lining of HNT which confirms its successful grafting on HNT. XRD patterns has revealed the nanocomposite having monoclinic structure in which it agrees with the FTIR results. The high surface area of 328.6 m2/g and high aspect ratio of the HNT-HFO nanocomposites has endowed it with enforcing ability and increased its water absorption capability, which in turn making it highly hydrophilic. The high hydrophilicity and adsorption ability of the nanoparticles has open a wide opportunity for it to be utilized in separation of wastewater.
Maryam Ghasemi; Somaye Mashhadi; Javad Azimi-Amin
Abstract
In this study, we have synthesized a new Fe3O4/AC nanocomposite using low cost adsorbent by microwave assisted in situ co-precipitation technique that was used as an effective adsorbent for the removal of methylene blue (MB) using the Taguchi design method as an optimization strategy. The optimum parameters ...
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In this study, we have synthesized a new Fe3O4/AC nanocomposite using low cost adsorbent by microwave assisted in situ co-precipitation technique that was used as an effective adsorbent for the removal of methylene blue (MB) using the Taguchi design method as an optimization strategy. The optimum parameters are pH 7, Fe3O4/AC nanocomposite dose 0.03 g, contact time 30 min, initial concentration of MB 25 mg/L and temperature 298 K. The obtained results of ANOVA show that their percent contribution in descending order is pH (66.81%) > adsorbent dose (25.54%) > temperature (4.83%) > initial MB concentration (1.23%) > contact time (0.32%). The kinetic data were fitted to the pseudo-first-order, pseudo-second-order and intra-particle diffusion models and adsorption of MB dye followed pseudo-second-order kinetic. The obtained values of regression coefficient for Langmuir (0.98), Frendluich (0.93) and Dubinin–Radushkevich (0.94) showed that adsorption process fits to the Langmuir isotherm and the maximum adsorption capacity is 384.6 mg/g. Moreover, the thermodynamics studies suggested the spontaneous nature of adsorption process.
Bal Yadav; Ritesh Kumar; Ravindra Kumar; Subhasis Chaudhuri; Panchanan Pramanik
Abstract
This paper presents the synthesis, characterization of the nanocomposite of silver and chitosan polymer composite reinforced by cellulose fibre and its electrical behaviour in presence of water vapour. The coated paper has been characterized by XRD, IR, SEM and EDX techniques. The size of silver nanoparticles ...
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This paper presents the synthesis, characterization of the nanocomposite of silver and chitosan polymer composite reinforced by cellulose fibre and its electrical behaviour in presence of water vapour. The coated paper has been characterized by XRD, IR, SEM and EDX techniques. The size of silver nanoparticles is found to be around 9 nm and deposited uniformly. Chitosan, as well as cellulose, contain a hydrogen attached to electronegative nitrogen and oxygen. This gives a favourable environment for the formation of hydrogen bonds. IR peaks of the composite infer the intermolecular hydrogen bonding between the two constituents. The SEM pictures show that the coating of the fibres with nanoparticles is quite uniform. EDX analysis shows that the coated filter paper has sufficient amount of silver along with carbon and oxygen. The coated paper shows good sensitivity towards humidity. It gives excellent linearity in response with a concentration of water vapour after heat treatment of composite at 130 °C. The sensitivity of the sensor is 0.8 MΩ per unit of relative humidity. Sensing properties originate from protonic conductivity from adsorbed water molecule.
Lida Rahmanzadeh; Mohsen Ghorbani; Mohsen Jahanshahi
Abstract
Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury adsorbent. The kinetics of adsorption depends on the adsorbent concentration, and the physical and chemical characteristics of adsorbent. In this study we were used a novel ...
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Mercury is one of the most toxic metals present in the environment. Adsorption has been proposed among the technologies for mercury adsorbent. The kinetics of adsorption depends on the adsorbent concentration, and the physical and chemical characteristics of adsorbent. In this study we were used a novel adsorbent, magnetite-polyrhodanine core- shell nanoparticles, for removing Hg(II) from aqueous solution. The effect of pH, initial Hg(II) concentration, initial adsorbent concentration and contact time on the efficiency of Hg(II) removal were investigated systematically by batch experiments. The maximum adsorption capacity was obtained 29.14 mg g-1 at PH=6.5 and 25°C with 10 g L-1 nano adsorbent. The kinetic data of adsorption of Hg(II) ion on the synthesized adsorbent were best described by a pseudo- second- order equation, indicating their chemical adsorption. The Freundlich, Langmuir and Temkin isotherms were used to modeling of mercury adsorption on Hg(II) in aqueous medium which modeled best by the Freundlich isotherm is whole concentration rage.
Samad Sabbaghi; Fateme Doraghi
Abstract
In this study, considering the importance of protecting the environment and preventing the pollution caused by industrial plants, a nanocomposite each component thereof is capable of removing the desired combination to solve this problem has been produced. To achieve this goal, ZnO/SnO2nanocomposite ...
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In this study, considering the importance of protecting the environment and preventing the pollution caused by industrial plants, a nanocomposite each component thereof is capable of removing the desired combination to solve this problem has been produced. To achieve this goal, ZnO/SnO2nanocomposite was synthesized using the co-precipitation method. The characterization of this nanocomposite was conducted by DLS, XRD, FTIR and SEM. The nanocomposite size was about 15nm. Several parameters such as the initial concentration of the wastewater, as well as the amount of catalyst and time were investigated. The reduction of the particle size due to an increase in the surface area of the nanocomposite increased the amount of decolorization. For all the performed experiments, the dye removal rate was 100% and the difference was to do with the time of the complete removal of methylene blue. A decrease in the concentration of methylene blue in the range of the tested concentrations reduced the decolorization, and by increasing the amount of nanocomposite in the range of the tested values, a decline in decolorization was observed.
Susan Samadi; Rokhsareh Motallebi; Maryam Nasiri Nasrabadi
Abstract
The efficient application of the photocatalytic activity and superficial adsorption on removing heavy metals from water, two types of sorbents, Nd-TiO2/bentonite and Ce-TiO2/bentonite nanocomposites, were synthesized by sol-gel method. The crystalline nanocomposites were obtained after heat treatment ...
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The efficient application of the photocatalytic activity and superficial adsorption on removing heavy metals from water, two types of sorbents, Nd-TiO2/bentonite and Ce-TiO2/bentonite nanocomposites, were synthesized by sol-gel method. The crystalline nanocomposites were obtained after heat treatment at 500 °C for 3 hours. The results of scanning electron microscopy (SEM) indicates that Nd-TiO2/bentonite and Ce-TiO2/bentonite were produced on a nanoscale. The phase change of both nanocomposite from amorphous to anatase has been investigated by X- ray diffraction. Removal of lead (II) and cadmium (II) were studied through adsorption on these nanocomposites by letting them float in the bulk of sample for a definite time in presence and absence of light. The effective parameters in removal process were studied and optimized. The optimum pH, removal time and sorbent dosage in the absence and presence of light for Pb2+ ion were 7, 0.3 g, 15 min and for Cd2+ ion were 7, 0.4 g, 20 min, respectively. Subsequently, the effect of interfering ions in removal process was investigated at optimum conditions and no evidence of interference was observed. The study showed that reproducibility of method (n=9) is good and suitable. The results further indicated that the removal efficiency of Pb2+ ion with Nd-TiO2/bentonite in the presence of light was more than that in the absence of light. Finally, the equilibrium adsorption data fitted Freundlich and Langmuir adsorption models.