Ashkan Zolriasatein; Sepideh Abdolahzadeh; Negar Motakef kazemi
Abstract
Nowadays, the water shortage has become a severe issue all over the world, especially in some arid and undeveloped areas. Water is a renewable natural resource that can produce freshwater globally. Interestingly, some animals in nature can collect water from fog, which can be the inspiration to develop ...
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Nowadays, the water shortage has become a severe issue all over the world, especially in some arid and undeveloped areas. Water is a renewable natural resource that can produce freshwater globally. Interestingly, some animals in nature can collect water from fog, which can be the inspiration to develop novel and functional water-collecting materials. A superhydrophobic surface that utilizes no energy has been synthesized from a water-collecting mechanism of the Stenocara beetles back structures. Firstly, this paper reviews the preparation methods of superhydrophobic surface coatings and then it examines patterns inspired by nature. In this paper, hydrophobic nanocoating was manufactured based on polyurethane (PUR) modified by nano-silica. Silica nanoparticles were synthesized via the sol-gel method. Then, silica nanoparticles were dispersed in polyurethane (PU) coatings. In this article, many factors of collecting moisture are evaluated, for example, temperature, pattern placement angle, pattern shape, types of surface patterns, and ambient humidity. Finally, are introduced the optimum situation for absorbing water from the fog.
Malak Barakat; Rassil Khoder; Fatima Kassir; Zeinab Harajli; Mouhiaddine Mohamed El Jamal; Azadeh Ebrahimian Pirbazari
Abstract
Sol–gel method was applied for synthesis of TiO2 nanoparticles in the existence of different volumes of ethanol (10–50 mL) with the purpose to find optimized synthesis conditions. Also, nickel doped TiO2 nanoparticles (Ni/TiO2 molar ratio: 0.1-1.0%) were prepared by the similar technique ...
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Sol–gel method was applied for synthesis of TiO2 nanoparticles in the existence of different volumes of ethanol (10–50 mL) with the purpose to find optimized synthesis conditions. Also, nickel doped TiO2 nanoparticles (Ni/TiO2 molar ratio: 0.1-1.0%) were prepared by the similar technique but in the existence of 10 mL ethanol and heated at different temperatures (300 °C –600 °C). XRD, SEM/EDX, UV-Vis DRS, FTIR and Raman spectroscopy were applied to identify the structural and morphological characteristics of the as-synthesized samples. XR diffraction results verified that TiO2 samples prepared with various volumes of ethanol (10–50 mL) consist of anatase and brookite phases up to 500 °C and rutile phase at 600 °C. The intensity of brookite diffraction decreased with the increase of calcination temperatures. Also, the low ethanol volume favored for formation of rutile phase at 600 °C. The addition of Ni(II) during the preparation of TiO2 nanoparticles prevented the formation of rutile phase. The undoped samples were synthesized with 10 and 20 mL ethanol and treated at 500 °C displayed the best catalytic performance for photocatalytic treatment of E 131 VF dye solution (rate constant: 0.051 and 0.061 (a.u) respectively). Ni doped TiO2 samples displayed lower photoactivity and rate constant.
Ashok V. Borhade; Dipak R. Tope; Jyoti A. Agashe; Sachin S. Kushare
Abstract
In the present work, the sol-gel derived powders of the chemical form FeCr2O4@ZnO@MgO Core-shell, has been synthesized and used as a photocatalyst. The synthesized core-shell nanoparticles characterized by various analytical techniques including FTIR, XRD, SEM-EDAX, and HR-TEM-SEAD. The successful performance ...
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In the present work, the sol-gel derived powders of the chemical form FeCr2O4@ZnO@MgO Core-shell, has been synthesized and used as a photocatalyst. The synthesized core-shell nanoparticles characterized by various analytical techniques including FTIR, XRD, SEM-EDAX, and HR-TEM-SEAD. The successful performance of synthesized core-shell photocatalyst FeCr2O4@ZnO@MgO has been also demonstrated for the complete mineralization of Orange G dye. The effect of various operational parameters used in dye degradation such as concentration of dye, light intensity, amount of photocatalyst, effect of light and effect of electrolyte has been studied on the rate of reaction. TEM analysis clearly shows two layers of ZnO and MgO on FeCr2O4. The highest degradation rate was found with concentration of Orange G dye 10 ppm, 0.8 g of FeCr2O4@ZnO@MgO and time 50 min. The recyclability of the photocatalyst, FeCr2O4@ZnO@MgO was performed up to four runs. The degradation mechanism has been established by using LC-MS analysis and it was used to track the numerous intermediate products formed during the course of Orange G dye degradation.
Kalpesh Isai; Vinod Shrivastava
Abstract
ZnO and 2%Fe-ZnO nanomaterials were prepared by using a low-cost sol-gel method. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The XRD and SEM studies reveal that the synthesized nanomaterials ...
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ZnO and 2%Fe-ZnO nanomaterials were prepared by using a low-cost sol-gel method. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The XRD and SEM studies reveal that the synthesized nanomaterials have a hexagonal wurtzite structure with average crystalline size ~ 22-23 nm. EDX analysis confirmed the composition and purity of synthesized nanomaterial. The photocatalytic activity of synthesized nanomaterials was monitored using the spectrophotometric method. Also, the photocatalytic removal of methylene blue (MB) dye from its aqueous solution by using ZnO and 2%Fe-ZnO nanopowder under UV light irradiation was studied. The effect of various parameters such as pH of dye solution, dye concentration, contact time and catalyst dose were investigated. Results of the current study demonstrated that, the maximum degradation using ZnO was 86 % and that for 2%Fe-ZnO was 92 % (under the optimum condition initial dye concentration=10 mg/L and pH =2). This study showed that 2%Fe-ZnO is a promising and better photocatalysts than ZnO.
Shimelis Kassahun; Zebene Kiflie; Dong Shin; Sam Park
Abstract
Although several studies concerning the preparation of nitrogen doped titanium dioxide visible-light active photocatalyst have already been reported, the effects of dopant concentration and calcination temperature have been rarely investigated. This paper focuses on the preparation of nitrogen ...
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Although several studies concerning the preparation of nitrogen doped titanium dioxide visible-light active photocatalyst have already been reported, the effects of dopant concentration and calcination temperature have been rarely investigated. This paper focuses on the preparation of nitrogen doped titanium dioxide (N-doped TiO2) under different calcination temperature and nitrogen dopant concentration synthesizes by sol-gel method. The physicochemical characteristics of the prepared samples were examined using X-ray photoelectron spectroscopy (XPS), X-ray diffractometer (XRD), Brunauer Emmett Teller (BET) analyzer, and UV-Vis spectrometer. Methylene blue was used in this study as a test chemical. The results demonstrated that the sample prepared under calcination temperature of 600 oC show 8.33 and 5.57 % of rutile TiO2 phase depends on the dopant concentration. Furthermore, the sample prepared at a lower calcination temperature of 400 oC and nitrogen to titanium (N/Ti) molar ratio of 2 and 6 exhibited larger specific surface area of 80.18 and 77.07 m2g-1, respectively. The photoactivity of the catalyst was also investigated on methylene blue decolorization using the different N-doped TiO2 sample. The experiments demonstrated that the sample prepared at higher N/Ti molar ratio (6) and lower calcination temperature (400 oC) demonstrates about 80 % efficiency under visible light. It was concluded that the higher photoactivity of the N-doped sample prepared at higher dopant concentration and lower calcination temperature is due to synergistic effects of higher surface area, smaller crystal size and higher nitrogen content in the crystal lattice of TiO2.