Mokhtar Ellali, A. M. Zenkour, M. Bouazza, N. Benseddiq
This contribution presents a new methodology and a new indeterminate integral variable of displacement field using trigonometric deformation in conjunction with gradient elasticity theory. The aim, for the first time, is to explore the thermal buckling behavior of functionally graded (FG) nanobeam thus elastic gradient theory takes into account the size effect on the critical thermal buckling load of FG nanobeams. Secondly, the impact of various factors, such as nonlocal coefficient, porosity parameter, material index, thermal loading type, and aspect ratio on the critical thermal buckling load of FG nanobeams. The material characteristics are considered to vary in thickness as the power law varies and the pore network is assumed to be empty or filled with low-pressure air.
{"title":"Thermal Buckling of FG Nanobeams via an Indeterminate Integral Variable with Trigonometric Displacement Models in Conjunction with the Gradient Elasticity Theory","authors":"Mokhtar Ellali, A. M. Zenkour, M. Bouazza, N. Benseddiq","doi":"10.4028/p-pconh6","DOIUrl":"https://doi.org/10.4028/p-pconh6","url":null,"abstract":"This contribution presents a new methodology and a new indeterminate integral variable of displacement field using trigonometric deformation in conjunction with gradient elasticity theory. The aim, for the first time, is to explore the thermal buckling behavior of functionally graded (FG) nanobeam thus elastic gradient theory takes into account the size effect on the critical thermal buckling load of FG nanobeams. Secondly, the impact of various factors, such as nonlocal coefficient, porosity parameter, material index, thermal loading type, and aspect ratio on the critical thermal buckling load of FG nanobeams. The material characteristics are considered to vary in thickness as the power law varies and the pore network is assumed to be empty or filled with low-pressure air.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140730465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Journal of Nano Research Vol. 82","authors":"","doi":"10.4028/b-q4i6qi","DOIUrl":"https://doi.org/10.4028/b-q4i6qi","url":null,"abstract":"","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140730803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Najih, N. Labchir, A. Tihane, Abdelfattah Narjis, L. Atourki, A. Elfanaoui, A. Ihlal
In this work, methylammonium lead halide CH3NH3PbI3 (MAPI3) perovskite nanorods were synthesized by the sol gel-spray ultrasonic method. The XRD pattern exhibits peaks assigned to the tetragonal MAPI3 structure with a residual PbI2 phase. SEM and AFM images show the formation of nanorods like picture with rough surface. The Raman spectrum was visualized to show various vibration modes in the film. Photoluminescence data revealed one emission peak at 786 nm (1.58 eV) in the band gap band, which was confirmed by the UV-Vis spectrum. The slight difference between the found band gap energy and the ideal one is explained in terms of shallow trap states.
{"title":"Synthesis and Optical Properties of CH3NH3PbI3 Nanorods with Defects States","authors":"H. Najih, N. Labchir, A. Tihane, Abdelfattah Narjis, L. Atourki, A. Elfanaoui, A. Ihlal","doi":"10.4028/p-fsoil4","DOIUrl":"https://doi.org/10.4028/p-fsoil4","url":null,"abstract":"In this work, methylammonium lead halide CH3NH3PbI3 (MAPI3) perovskite nanorods were synthesized by the sol gel-spray ultrasonic method. The XRD pattern exhibits peaks assigned to the tetragonal MAPI3 structure with a residual PbI2 phase. SEM and AFM images show the formation of nanorods like picture with rough surface. The Raman spectrum was visualized to show various vibration modes in the film. Photoluminescence data revealed one emission peak at 786 nm (1.58 eV) in the band gap band, which was confirmed by the UV-Vis spectrum. The slight difference between the found band gap energy and the ideal one is explained in terms of shallow trap states.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140728140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Prince Oppong Amoh, Ahmed Elwardany, Manabu Fujii, H. Shokry
Room temperature-built gas sensors were fabricated from graphene oxide (GO), pristine and doped SnO2 nanostructures. The as-synthesized green carbon derivative (GO) nanomaterials were prepared from waste plastic precursor using Modified Hummer’s methodology. Pristine SnO2 and GO-SnO2 nanocomposite were synthesized employing a wet synthesis technique known as co-precipitation. The as-prepared nanoparticles were investigated for structural crystallographic and morphological features using X-ray diffractometry (XRD) and Transmission electron microscopy (TEM) analytical techniques. High-angle annular dark field (HAADF) and elemental quantifications of the nanopowders were investigated with the Energy dispersive X-ray spectroscopy (EDX). Textural features were determined with the assistance of Brunauer-Emmett-Teller (BET) analyzer. Thermogravimetric analysis (TGA) was performed to ascertain the material stability and degradability of the synthetic materials. Functional group and bond structure analysis was conducted using Fourier-transform infrared (FTIR) spectroscopy. Gas sensor devices were tested for responses towards CH4, H2, LPG, and CO2 gases at 20 ppm concentrations of each. GO-SnO2 nanocomposite sensing device showed optimal detection response towards the respective analyte gases with values of 5.00, 5.08, 4.90 and 3.41 respectively. The prepared nanocomposite showed stability and selectivity towards the target gases in an order of magnitude of H2 > CH4 > LPG > CO2. The optimal gas sensor device’s dynamic gas sensing response was ascribed to the GO doping effect which relatively increased its surface area (46.48 m2g-1) and absorption sites.
利用氧化石墨烯（GO）、原始和掺杂二氧化锡纳米结构制作了室温气体传感器。采用改良悍马法，从废塑料前驱体中制备出合成绿色碳衍生物（GO）纳米材料。利用湿合成技术（即共沉淀法）合成了原始二氧化锡和 GO-SnO2 纳米复合材料。利用 X 射线衍射仪（XRD）和透射电子显微镜（TEM）分析技术研究了制备的纳米粒子的结构晶体学和形态特征。利用能量色散 X 射线光谱（EDX）对纳米粉体的高角度环形暗场（HAADF）和元素定量进行了研究。在布鲁纳-艾美特-泰勒（BET）分析仪的帮助下确定了纹理特征。为了确定合成材料的稳定性和降解性，还进行了热重分析（TGA）。使用傅立叶变换红外（FTIR）光谱进行了官能团和键结构分析。测试了气体传感器装置对 CH4、H2、LPG 和 CO2 每种气体 20 ppm 浓度的反应。GO-SnO2 纳米复合材料传感装置对相应分析气体的检测响应最佳，分别为 5.00、5.08、4.90 和 3.41。所制备的纳米复合材料对目标气体的稳定性和选择性依次为 H2 > CH4 > LPG > CO2。最佳气体传感器装置的动态气体传感响应归因于 GO 的掺杂效应，这相对增加了其表面积（46.48 m2g-1）和吸收位点。
{"title":"Room Temperature-Built Gas Sensors from Green Carbon Derivative: A Comparative Study between Pristine SnO2 and GO-SnO2 Nanocomposite","authors":"Prince Oppong Amoh, Ahmed Elwardany, Manabu Fujii, H. Shokry","doi":"10.4028/p-8hb3rr","DOIUrl":"https://doi.org/10.4028/p-8hb3rr","url":null,"abstract":"Room temperature-built gas sensors were fabricated from graphene oxide (GO), pristine and doped SnO2 nanostructures. The as-synthesized green carbon derivative (GO) nanomaterials were prepared from waste plastic precursor using Modified Hummer’s methodology. Pristine SnO2 and GO-SnO2 nanocomposite were synthesized employing a wet synthesis technique known as co-precipitation. The as-prepared nanoparticles were investigated for structural crystallographic and morphological features using X-ray diffractometry (XRD) and Transmission electron microscopy (TEM) analytical techniques. High-angle annular dark field (HAADF) and elemental quantifications of the nanopowders were investigated with the Energy dispersive X-ray spectroscopy (EDX). Textural features were determined with the assistance of Brunauer-Emmett-Teller (BET) analyzer. Thermogravimetric analysis (TGA) was performed to ascertain the material stability and degradability of the synthetic materials. Functional group and bond structure analysis was conducted using Fourier-transform infrared (FTIR) spectroscopy. Gas sensor devices were tested for responses towards CH4, H2, LPG, and CO2 gases at 20 ppm concentrations of each. GO-SnO2 nanocomposite sensing device showed optimal detection response towards the respective analyte gases with values of 5.00, 5.08, 4.90 and 3.41 respectively. The prepared nanocomposite showed stability and selectivity towards the target gases in an order of magnitude of H2 > CH4 > LPG > CO2. The optimal gas sensor device’s dynamic gas sensing response was ascribed to the GO doping effect which relatively increased its surface area (46.48 m2g-1) and absorption sites.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140730703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. O. Ajayi, M. Ogbonnaya, Oge Ogo-Ozegbe, A. P. Popoola
Waste management has been a major concern in the society and agricultural wastes can be utilized in the synthesis of nanoparticles and deployed in the vapour compression refrigeration system (VCRS) to enhance its performance. This study analysed the thermophysical properties, performance, energy consumption, pull-down time, and capacities of VCRS using bio-nanoparticles produced from orange and pineapple peels. Eco-friendly refrigerants R600a and R134a with pure polyolester (POE) as the lubricating oil for the compressor were used. The nanolubricants were dispersed in three volume fractions of 0.05%, 0.10% and 0.20% concentration in the lubricant using the two-step method. The degradation of nanolubricants were analysed by examining the thermophysical properties of the nanolubricants before and after use in the VCRS. At 0.2% volume concentration, optimum COP of 6.31 and 5.01 were obtained for pineapple and orange peels respectively for R600a. The nanolubricants of orange peels with the volume fraction of 0.2% had the best pull-down time with a temperature of-2oC. The lowest power consumption was observed for 0.1% volume concentration of pineapple nanolubricants while 0.2% volume concentration of orange nanolubricants was observed to have the least power consumption. Considering the R134a refrigerant, the volume concentration with the optimum COP was 0.1 vol% concentration for the orange bio-based nanolubricants with an increase in the COP of 36.3% when compared with pure R134a while 0.2 vol% had the best pull-down time with a temperature of-3oC. There was a 14.2% drop in the power consumption of 0.1 vol% concentration of pineapple nanolubricants when compared to the various concentrations of the bio-based nanolubricants. From this study, the optimum performance was observed at 0.20 vol% concentration for the orange and pineapple nanolubricants with a relatively less power consumption. R600a refrigerant can completely replace R134a in its use in refrigeration systems and achieve similar pull-down time and coefficient of performance when bio-nanolubricants are utilized in the systems.
{"title":"Agricultural Waste Valorization for Nanoparticles Synthesis and Enhancement of Vapour Compression Refrigeration System’s Performance","authors":"O. O. Ajayi, M. Ogbonnaya, Oge Ogo-Ozegbe, A. P. Popoola","doi":"10.4028/p-n0ymvc","DOIUrl":"https://doi.org/10.4028/p-n0ymvc","url":null,"abstract":"Waste management has been a major concern in the society and agricultural wastes can be utilized in the synthesis of nanoparticles and deployed in the vapour compression refrigeration system (VCRS) to enhance its performance. This study analysed the thermophysical properties, performance, energy consumption, pull-down time, and capacities of VCRS using bio-nanoparticles produced from orange and pineapple peels. Eco-friendly refrigerants R600a and R134a with pure polyolester (POE) as the lubricating oil for the compressor were used. The nanolubricants were dispersed in three volume fractions of 0.05%, 0.10% and 0.20% concentration in the lubricant using the two-step method. The degradation of nanolubricants were analysed by examining the thermophysical properties of the nanolubricants before and after use in the VCRS. At 0.2% volume concentration, optimum COP of 6.31 and 5.01 were obtained for pineapple and orange peels respectively for R600a. The nanolubricants of orange peels with the volume fraction of 0.2% had the best pull-down time with a temperature of-2oC. The lowest power consumption was observed for 0.1% volume concentration of pineapple nanolubricants while 0.2% volume concentration of orange nanolubricants was observed to have the least power consumption. Considering the R134a refrigerant, the volume concentration with the optimum COP was 0.1 vol% concentration for the orange bio-based nanolubricants with an increase in the COP of 36.3% when compared with pure R134a while 0.2 vol% had the best pull-down time with a temperature of-3oC. There was a 14.2% drop in the power consumption of 0.1 vol% concentration of pineapple nanolubricants when compared to the various concentrations of the bio-based nanolubricants. From this study, the optimum performance was observed at 0.20 vol% concentration for the orange and pineapple nanolubricants with a relatively less power consumption. R600a refrigerant can completely replace R134a in its use in refrigeration systems and achieve similar pull-down time and coefficient of performance when bio-nanolubricants are utilized in the systems.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140731873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nafion®/silica nanocomposite membranes were prepared by impregnation method from Nafion® 117 and sol-gel pre-synthesized n-octadecyl-trimethoxy silane (C18TMS) coated silica nanoparticles. The scanning electron microscope (SEM) of pristine silica particles displayed monodispersed nanospheres with diameters ranging from 150-350 nm; while Brunauer-Emmett-Teller (BET) analysis presented 760 m2/g BET surface area, a micropore-mesopore bimodal distribution of micropore systems with respective pore volume at 14.6 Å and 17.0 Å (2.01 x 10-3 cm3/g.Å), as well as the prolific mesopores centered at 29.5 Å (5.64 x 10-2 cm3/g.Å). Characterization of Nafion® 117 based membranes on SEM, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and x-ray diffraction (XRD), and tensile stress exhibited varying surface morphology with silica loadings, structural interaction between membrane support and the ion exchanger, thermal stabilities (up to 330 °C), crystalline nature, and reasonable mechanical stability of nanocomposite membranes. The maximum water uptake (44.8 %) and proton conductivity of (1.14 x10-2 S/cm) were obtained on low Nafion®/SiO2 (5%) loaded membrane. While both composite membranes displayed the improved reduction in methanol permeability, 2.43x10-07 cm2/s at 80 °C was obtained with high Nafion®/SiO2 (10%) loading. Improved water uptake and proton conductivity substantiate the high ion exchange capacity (IEC) of 1.81 meq.g-1 when compared to IEC of 0.93 meq.g-1 [pristine Nafion®] and 1.46 meq.g-1 [Nafion®/SiO2 (10%)]. The increase in IEC value may be due to the high acid functionalization of additional sulfonic acid groups surrounded by hydrophilic segments of nanosilica, which improves the properties of the membrane. The high proton conductivity coupled with great water retention capabilities indicated that the Nafion®/SiO2 nanocomposite membranes could be utilized as proton exchange membranes for medium temperature methanol fuel cells. Keywords: Fuel cells; nanocomposite membrane; SiO2 nanofillers; methanol permeability; ion exchange capacity
{"title":"Synthesis and Characterization of Enhanced Proton-Conducting Nafion® 117- Silica Composite Membranes for Fuel Cell Applications","authors":"Mayetu E. Segale, T. Mokrani, R. Sigwadi","doi":"10.4028/p-3lgu0l","DOIUrl":"https://doi.org/10.4028/p-3lgu0l","url":null,"abstract":"Nafion®/silica nanocomposite membranes were prepared by impregnation method from Nafion® 117 and sol-gel pre-synthesized n-octadecyl-trimethoxy silane (C18TMS) coated silica nanoparticles. The scanning electron microscope (SEM) of pristine silica particles displayed monodispersed nanospheres with diameters ranging from 150-350 nm; while Brunauer-Emmett-Teller (BET) analysis presented 760 m2/g BET surface area, a micropore-mesopore bimodal distribution of micropore systems with respective pore volume at 14.6 Å and 17.0 Å (2.01 x 10-3 cm3/g.Å), as well as the prolific mesopores centered at 29.5 Å (5.64 x 10-2 cm3/g.Å). Characterization of Nafion® 117 based membranes on SEM, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and x-ray diffraction (XRD), and tensile stress exhibited varying surface morphology with silica loadings, structural interaction between membrane support and the ion exchanger, thermal stabilities (up to 330 °C), crystalline nature, and reasonable mechanical stability of nanocomposite membranes. The maximum water uptake (44.8 %) and proton conductivity of (1.14 x10-2 S/cm) were obtained on low Nafion®/SiO2 (5%) loaded membrane. While both composite membranes displayed the improved reduction in methanol permeability, 2.43x10-07 cm2/s at 80 °C was obtained with high Nafion®/SiO2 (10%) loading. Improved water uptake and proton conductivity substantiate the high ion exchange capacity (IEC) of 1.81 meq.g-1 when compared to IEC of 0.93 meq.g-1 [pristine Nafion®] and 1.46 meq.g-1 [Nafion®/SiO2 (10%)]. The increase in IEC value may be due to the high acid functionalization of additional sulfonic acid groups surrounded by hydrophilic segments of nanosilica, which improves the properties of the membrane. The high proton conductivity coupled with great water retention capabilities indicated that the Nafion®/SiO2 nanocomposite membranes could be utilized as proton exchange membranes for medium temperature methanol fuel cells. Keywords: Fuel cells; nanocomposite membrane; SiO2 nanofillers; methanol permeability; ion exchange capacity","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140732418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study reports on the amperometric sensing properties of FeO/Fe2O3 thin films for the detection of Allura Red (AR) and Direct Blue 15 (DB15) Azo dyes. The FeO/Fe2O3 thin films were produced using the Sequential Ionic Layer Adsorption and Reaction (SILAR) method and Na+-doping. The morphological and structural properties of the nanocomposites produced at pH of 10.5 showed good properties for the detection of azo dyes. The linear curve fit equations for AR and DB15 droplet applications onto Na+-doped FeO nanocomposite thin film samples were found to be y = -0.0002x + 0.0043 (R² = 0.9143) and y = -7E-05x + 0.0005 (R² = 0.9809), respectively. The findings reveal that adding Na+ doping to FeO/Fe2O3 thin films can effectively increase the detection response for the target azo dyes and enhance the sensitivity of the sensing system. The results suggest that the SILAR method can be used to produce low-cost and reusable FeO/Fe2O3 thin film devices, which can be promising candidates for the detection of toxic azo dyes in liquid samples.
本研究报告了用于检测 Allura Red (AR) 和 Direct Blue 15 (DB15) 偶氮染料的 FeO/Fe2O3 薄膜的安培传感特性。FeO/Fe2O3 薄膜是采用序离子层吸附和反应（SILAR）法和 Na+ 掺杂法制备的。在 pH 值为 10.5 的条件下制备的纳米复合材料的形态和结构特性显示出良好的偶氮染料检测性能。将 AR 和 DB15 液滴应用于掺杂 Na+ 的 FeO 纳米复合薄膜样品的线性曲线拟合方程分别为 y = -0.0002x + 0.0043 (R² = 0.9143) 和 y = -7E-05x + 0.0005 (R² = 0.9809)。研究结果表明，在 FeO/Fe2O3 薄膜中掺入 Na+ 能有效提高目标偶氮染料的检测响应，并提高传感系统的灵敏度。结果表明，SILAR 方法可用于生产低成本、可重复使用的 FeO/Fe2O3 薄膜器件，有望用于检测液体样品中的有毒偶氮染料。
{"title":"A Study of Nanostructured FeO Thin Film-Based Allure Red and Direct Blue 15 Azo Dyes Sensing Scheme","authors":"Sumeyra Gunduz, Azize Alayli, Harun Guney, Omer Coban, Mehmet Ertuğrul, Hayrunnisa Nadaroğlu","doi":"10.4028/p-dz4n68","DOIUrl":"https://doi.org/10.4028/p-dz4n68","url":null,"abstract":"This study reports on the amperometric sensing properties of FeO/Fe2O3 thin films for the detection of Allura Red (AR) and Direct Blue 15 (DB15) Azo dyes. The FeO/Fe2O3 thin films were produced using the Sequential Ionic Layer Adsorption and Reaction (SILAR) method and Na+-doping. The morphological and structural properties of the nanocomposites produced at pH of 10.5 showed good properties for the detection of azo dyes. The linear curve fit equations for AR and DB15 droplet applications onto Na+-doped FeO nanocomposite thin film samples were found to be y = -0.0002x + 0.0043 (R² = 0.9143) and y = -7E-05x + 0.0005 (R² = 0.9809), respectively. The findings reveal that adding Na+ doping to FeO/Fe2O3 thin films can effectively increase the detection response for the target azo dyes and enhance the sensitivity of the sensing system. The results suggest that the SILAR method can be used to produce low-cost and reusable FeO/Fe2O3 thin film devices, which can be promising candidates for the detection of toxic azo dyes in liquid samples.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140728896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Structural, Morphologycal and Wettability of SiliconNanowires (SiNWs) elaborated using Ag assisted electroless chemical etching are investigated. Prior the etching, Ag nanoparticles (AgNPs) were deposited at room temperature in a HF/AgNO3 solution with different concentration of AgNO3. The XRD spectra of the Ag NPs deposit show a good crystallinity. The effects of temperature etching bath and concentrations of AgNO3 on the etching process were examined. The morphological study, performed using a Scanning Electron Microscopy (SEM), shows porous silicon layer of 2µm for the lower temperature etching. For 25°C, perpendicular silicon nanowires about 15µm were formed. For the higher etching temperature (50°C), the silicon nanowire about 50 nm in diameter and 50µm in length were formed. The impact of Ag concentration on the SiNWs formation is examined in the second part of the present work. It is shown that the etching depth decreases as the Ag concentration decreases with values of 2.8 μm and 2 μm for concentrations of 0.025M and 0.0125M, respectively. The hydrophobicity of the samples was monitored by measuring the contact angle between a drop of water and the sample surface. It was established that the morphology is strongly influenced by etching conditions and their wettability changes from superhydrophilic to hydrophobic. FTIR analysis confirms the oxide-free silicon nanowires.
{"title":"Temperature Etching and Metallic Agent Concentration Effect on Structure, Morphology and Wettability of Silicon Nanowires","authors":"Sabrina Lamrani, T. Hadjersi, Saifi Amirouche, Nesrine Oussaf, Mourad Mebarki, Rouaya Belhoucif","doi":"10.4028/p-f5zwhy","DOIUrl":"https://doi.org/10.4028/p-f5zwhy","url":null,"abstract":"Abstract. Structural, Morphologycal and Wettability of SiliconNanowires (SiNWs) elaborated using Ag assisted electroless chemical etching are investigated. Prior the etching, Ag nanoparticles (AgNPs) were deposited at room temperature in a HF/AgNO3 solution with different concentration of AgNO3. The XRD spectra of the Ag NPs deposit show a good crystallinity. The effects of temperature etching bath and concentrations of AgNO3 on the etching process were examined. The morphological study, performed using a Scanning Electron Microscopy (SEM), shows porous silicon layer of 2µm for the lower temperature etching. For 25°C, perpendicular silicon nanowires about 15µm were formed. For the higher etching temperature (50°C), the silicon nanowire about 50 nm in diameter and 50µm in length were formed. The impact of Ag concentration on the SiNWs formation is examined in the second part of the present work. It is shown that the etching depth decreases as the Ag concentration decreases with values of 2.8 μm and 2 μm for concentrations of 0.025M and 0.0125M, respectively. The hydrophobicity of the samples was monitored by measuring the contact angle between a drop of water and the sample surface. It was established that the morphology is strongly influenced by etching conditions and their wettability changes from superhydrophilic to hydrophobic. FTIR analysis confirms the oxide-free silicon nanowires.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140729182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Al Qahoom, K. El Kihel, R. Aharrouch, Abdalhameed Al-Rajhi, Mohamed Madani, M. El Bouziani
In this paper, the ferrimagnetic mixed spins (1, 5/2) Blume-Capel model is proposed to investigate the phase diagrams and hysteresis behaviors of a magnetic cylindrical nanotube with a core-shell structure using the mean-field approximation based on the Bogoliubov inequality for the Gibbs free energy. The core sites are occupied by σ= ±1, 0 spins, whereas the shell sites are filled by S= ±5/2, ±3/2, ±1/2 spins. The effects of exchange couplings (Jin, JS) and single-ion anisotropies (DC, DS) on core, shell, and total magnetizations are investigated, as well as hysteresis behaviors. The entropy, free energy, and specific heat are analyzed to establish the stability of the solutions. The presentation and discussion of phase diagrams is detailed. The system shows a first-order and second-order phase transitions, as well as tricritical and critical end- points. In addition, the system shows compensation and reentrant behaviors. Various multiple hysteresis loop behaviors are seen according on the Hamiltonian parameters, such as the presence of triple, quintuple, and septuple hysteresis loops.
{"title":"Mean Field Study of a Cylindrical Ferrimagnetic Nanotube with Different Anisotropies","authors":"Y. Al Qahoom, K. El Kihel, R. Aharrouch, Abdalhameed Al-Rajhi, Mohamed Madani, M. El Bouziani","doi":"10.4028/p-hst2ye","DOIUrl":"https://doi.org/10.4028/p-hst2ye","url":null,"abstract":"In this paper, the ferrimagnetic mixed spins (1, 5/2) Blume-Capel model is proposed to investigate the phase diagrams and hysteresis behaviors of a magnetic cylindrical nanotube with a core-shell structure using the mean-field approximation based on the Bogoliubov inequality for the Gibbs free energy. The core sites are occupied by σ= ±1, 0 spins, whereas the shell sites are filled by S= ±5/2, ±3/2, ±1/2 spins. The effects of exchange couplings (Jin, JS) and single-ion anisotropies (DC, DS) on core, shell, and total magnetizations are investigated, as well as hysteresis behaviors. The entropy, free energy, and specific heat are analyzed to establish the stability of the solutions. The presentation and discussion of phase diagrams is detailed. The system shows a first-order and second-order phase transitions, as well as tricritical and critical end- points. In addition, the system shows compensation and reentrant behaviors. Various multiple hysteresis loop behaviors are seen according on the Hamiltonian parameters, such as the presence of triple, quintuple, and septuple hysteresis loops.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Julia Mazurenko, L. Kaykan, K. SijoA., M. Moiseienko, Myroslav Kuzyshyn, Nataliia Ostapovych, Mariia Moklyak
Nanoscale mixed ferrites with a spinel structure are highly versatile materials widely employed across diverse fields, including engineering, biomedicine, and ecology. This study explores the influence of pH on the structure, morphology, electrophysical, and mechanical properties of CuFe2O4 spinel, synthesized using the sol-gel self-combustion method. The investigation reveals that the pH level significantly impacts the structure formation, even at the gel formation stage, thereby shaping the subsequent structure and properties of the synthesized ferrite. X-ray diffraction (XRD) analysis demonstrates that the dominant phase (>90%) corresponds to the cubic spinel phase with the chemical formula CuFe2O4, belonging to the Fd3m space group. Notably, the pH of the reaction medium exerts a profound influence on the distribution of iron and copper ions within the octahedral and tetrahedral sublattices of the spinel structure. This variation in cationic distribution manifests in notable changes in the synthesized ferrite's magnetic, mechanical, and degradation properties. Furthermore, the study delves into the impact of the synthesized CuFe2O4 spinel as a photocatalyst for degrading organic dyes through the photo-Fenton process. It demonstrates that degradation efficiency is closely related to the ferrite's band gap width and particle size. This study aimed to determine how the pH of the reaction medium impacts the structure, morphology, optical, mechanical, and magnetic characteristics of the nanosized ferrites being synthesized. Furthermore, the synthesized materials were evaluated for their photocatalytic abilities in degrading organic dyes in water. The ferrite powders showcased remarkable dye degradation capabilities via the photo-Fenton process. Degradation efficiency largely hinged on the band gap width and the size of the particles. The most notable outcome was achieved with sample P1, which had particle sizes averaging 12.14 nm. By unraveling the complex relationship between pH, structure, and properties, this research enhances our understanding of the design and optimization of nanoscale mixed ferrites.
{"title":"The Influence of Reaction Medium pH on the Structure, Optical, and Mechanical Properties of Nanosized Cu-Fe Ferrite Synthesized by the Sol-Gel Autocombustion Method","authors":"Julia Mazurenko, L. Kaykan, K. SijoA., M. Moiseienko, Myroslav Kuzyshyn, Nataliia Ostapovych, Mariia Moklyak","doi":"10.4028/p-d2fqah","DOIUrl":"https://doi.org/10.4028/p-d2fqah","url":null,"abstract":"Nanoscale mixed ferrites with a spinel structure are highly versatile materials widely employed across diverse fields, including engineering, biomedicine, and ecology. This study explores the influence of pH on the structure, morphology, electrophysical, and mechanical properties of CuFe2O4 spinel, synthesized using the sol-gel self-combustion method. The investigation reveals that the pH level significantly impacts the structure formation, even at the gel formation stage, thereby shaping the subsequent structure and properties of the synthesized ferrite. X-ray diffraction (XRD) analysis demonstrates that the dominant phase (>90%) corresponds to the cubic spinel phase with the chemical formula CuFe2O4, belonging to the Fd3m space group. Notably, the pH of the reaction medium exerts a profound influence on the distribution of iron and copper ions within the octahedral and tetrahedral sublattices of the spinel structure. This variation in cationic distribution manifests in notable changes in the synthesized ferrite's magnetic, mechanical, and degradation properties. Furthermore, the study delves into the impact of the synthesized CuFe2O4 spinel as a photocatalyst for degrading organic dyes through the photo-Fenton process. It demonstrates that degradation efficiency is closely related to the ferrite's band gap width and particle size. This study aimed to determine how the pH of the reaction medium impacts the structure, morphology, optical, mechanical, and magnetic characteristics of the nanosized ferrites being synthesized. Furthermore, the synthesized materials were evaluated for their photocatalytic abilities in degrading organic dyes in water. The ferrite powders showcased remarkable dye degradation capabilities via the photo-Fenton process. Degradation efficiency largely hinged on the band gap width and the size of the particles. The most notable outcome was achieved with sample P1, which had particle sizes averaging 12.14 nm. By unraveling the complex relationship between pH, structure, and properties, this research enhances our understanding of the design and optimization of nanoscale mixed ferrites.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2023-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138944219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：