This present study is intended for a CFD analysis of hydrodynamic and thermal characteristics of water-based fluid containing TiO2 or CuO nanoparticles flowing in laminar regime in a 3D uniformly heated horizontal annulus utilizing several. Four distinct models have been developed using various combinations (A, B, C and D) of the available theorical-based and experimental-based thermal conductivity and viscosity correlations. A CFD-Fortran code based on the finite volume technique was elaborated for the numerical solution of the mathematical model of the problem. The implications of Grashof number, volume fraction, and type of nanoparticle on isovelocity, isotherms, mean and wall temperatures, Nusselt number, heat transfer coefficient, pressure drop, and thermal performance evaluation criteria are explored using these different models. The results demonstrate that the Nusselt number and heat transfer coefficient of all developed models improve with the addition of nanoparticles. For 2% of nanoparticles’ concentration, the largest enhancement was reached for model D by about 23.5% with respect to the based liquid, while the smallest enhancement was obtained for model B by about 1.16%. The highest Performance Evaluation Criteria (PEC) are attained by employing model D by about 1.263, followed by model C by about 1.074.
{"title":"Heat Transfer Investigation of Laminar Flow Mixed Convection of Nanofluids in a Uniformly Heated Horizontal Annulus: A Combination of Theoretical-Based and Experimental-Based Models of Thermal Conductivity and Viscosity","authors":"Mohammed Benkhedda, T. Tayebi, Ali J. Chamkha","doi":"10.4028/p-85299u","DOIUrl":"https://doi.org/10.4028/p-85299u","url":null,"abstract":"This present study is intended for a CFD analysis of hydrodynamic and thermal characteristics of water-based fluid containing TiO2 or CuO nanoparticles flowing in laminar regime in a 3D uniformly heated horizontal annulus utilizing several. Four distinct models have been developed using various combinations (A, B, C and D) of the available theorical-based and experimental-based thermal conductivity and viscosity correlations. A CFD-Fortran code based on the finite volume technique was elaborated for the numerical solution of the mathematical model of the problem. The implications of Grashof number, volume fraction, and type of nanoparticle on isovelocity, isotherms, mean and wall temperatures, Nusselt number, heat transfer coefficient, pressure drop, and thermal performance evaluation criteria are explored using these different models. The results demonstrate that the Nusselt number and heat transfer coefficient of all developed models improve with the addition of nanoparticles. For 2% of nanoparticles’ concentration, the largest enhancement was reached for model D by about 23.5% with respect to the based liquid, while the smallest enhancement was obtained for model B by about 1.16%. The highest Performance Evaluation Criteria (PEC) are attained by employing model D by about 1.263, followed by model C by about 1.074.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"55 1","pages":"103 - 144"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73777604","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}
Hydrogen evolution reactions (HER) are important in a variety of electrochemical devices, such as electrolysers and fuel cells. To reduce the reaction overpotential and reduce energy consumption, efficient, low-cost, and durable electrocatalysts must be developed. Needle-less electrospinning (NLE) technique was used to prepare the fibrous electrocatalyst. NLE is a user-friendly and adaptable technique for large-scale low-cost fiber production. NLE created transition metal phosphides carbon fibers (TMP CF). The precursor foam was folded between two Al2O3 ceramic plates. The heat treatment was carried out in a tube furnace at 1200 °C in an Ar atmosphere, followed by a reduction in an H2 atmosphere at 780 °C. The electrolyser's membrane electrode assembly can be immediately submerged in the final TMP CF in the form of plates. The created NiCoP catalytic plates could be directly used in electrolyser's membrane electrode assembly of PEM electrolysers. In a three-electrode system, the electrochemical activity of the produced electrocatalysts was evaluated using linear sweep voltammetry. The electrochemical activity of the produced electrocatalysts were evaluated using linear sweep voltammetry. The catalyst's stability and endurance in acidic and alkaline environments were investigated.
{"title":"Carbon Fibers Doped by Binary Phosphides as an Electrocatalytic Layer for PEM Electrolysers","authors":"Cyril Bera, Magdalena Streckova","doi":"10.4028/p-o8u8bx","DOIUrl":"https://doi.org/10.4028/p-o8u8bx","url":null,"abstract":"Hydrogen evolution reactions (HER) are important in a variety of electrochemical devices, such as electrolysers and fuel cells. To reduce the reaction overpotential and reduce energy consumption, efficient, low-cost, and durable electrocatalysts must be developed. Needle-less electrospinning (NLE) technique was used to prepare the fibrous electrocatalyst. NLE is a user-friendly and adaptable technique for large-scale low-cost fiber production. NLE created transition metal phosphides carbon fibers (TMP CF). The precursor foam was folded between two Al2O3 ceramic plates. The heat treatment was carried out in a tube furnace at 1200 °C in an Ar atmosphere, followed by a reduction in an H2 atmosphere at 780 °C. The electrolyser's membrane electrode assembly can be immediately submerged in the final TMP CF in the form of plates. The created NiCoP catalytic plates could be directly used in electrolyser's membrane electrode assembly of PEM electrolysers. In a three-electrode system, the electrochemical activity of the produced electrocatalysts was evaluated using linear sweep voltammetry. The electrochemical activity of the produced electrocatalysts were evaluated using linear sweep voltammetry. The catalyst's stability and endurance in acidic and alkaline environments were investigated.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"214 1","pages":"97 - 102"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78404741","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}
J. Junaidi, Wiwin Sulistiani, Yessi Efridahniar, I. Pratiwi, I. Firdaus, P. Manurung, P. Karo Karo
In this study, silver-silica (Ag/SiO2) was synthesized using the sol-gel method by silica from rice husks. Silica derived from rice husk waste was previously synthesized using the sol gel method. In addition, the Ag material used in this study was also performed into silver nanoparticles (AgNPs). This method was chosen to obtain an Ag/SiO2 composite with nano size and high purity. AgNPs were synthesized using silver nitrate (AgNO3) by reduction method at 90 °C. The reducing agent and stabilizer used is trisodium citrate. UV-Vis, FTIR, XRD, and SEM-EDX were used for the analysis Ag/SiO2 composites. Uv-Vis analysis results Ag/SiO2 has an absorption peak at a wavelength of 412 nm with a bandgap energy of 2.25 eV. These peaks indicate that AgNPs have formed in the SiO2 membrane. The FTIR results revealed the Si-O-Si bonds which indicated the presence of silica and the Ag-O functional group, and the presence of AgNPs. The results of XRD analysis showed that the silica structure formed was cristobalite and silver crystals in the face center cubic (fcc) shape. The results of the SEM-EDX morphological analysis showed that the Ag/SiO2 nanocomposite was shaped like sharp stone chips and the presence of small granules (granules) with different particle sizes and shapes, slightly porous and the composition of the compounds in the Ag/SiO2 nanocomposite indicated the presence of various chemical elements in the sample, including carbon, oxygen, sodium, silica, and silver.
本研究以稻壳为原料，采用溶胶-凝胶法制备了银硅(Ag/SiO2)。以前用溶胶-凝胶法从稻壳废料中合成二氧化硅。此外，本研究中使用的银材料也被制成银纳米颗粒(AgNPs)。采用该方法制备了具有纳米尺寸和高纯度的Ag/SiO2复合材料。以硝酸银(AgNO3)为原料，在90℃下采用还原法制备AgNPs。所用还原剂和稳定剂为柠檬酸三钠。采用UV-Vis、FTIR、XRD、SEM-EDX对Ag/SiO2复合材料进行分析。紫外可见光谱分析结果Ag/SiO2在412 nm处有一个吸收峰，能带能为2.25 eV。这些峰表明AgNPs已经在SiO2膜中形成。FTIR结果显示硅- o - si键表明存在二氧化硅和Ag-O官能团，以及AgNPs的存在。XRD分析结果表明，所形成的二氧化硅结构为方英石和银晶体，呈面心立方(fcc)状。SEM-EDX形貌分析结果表明，Ag/SiO2纳米复合材料呈锋利的石屑状，存在不同粒径和形状的小颗粒(颗粒)，微多孔，Ag/SiO2纳米复合材料中化合物的组成表明样品中存在多种化学元素，包括碳、氧、钠、二氧化硅和银。
{"title":"Synthesis and Characterization of Ag/SiO2 Nanocomposite Based on Rice Husk Silica Using Sol-Gel Method","authors":"J. Junaidi, Wiwin Sulistiani, Yessi Efridahniar, I. Pratiwi, I. Firdaus, P. Manurung, P. Karo Karo","doi":"10.4028/p-54swgk","DOIUrl":"https://doi.org/10.4028/p-54swgk","url":null,"abstract":"In this study, silver-silica (Ag/SiO2) was synthesized using the sol-gel method by silica from rice husks. Silica derived from rice husk waste was previously synthesized using the sol gel method. In addition, the Ag material used in this study was also performed into silver nanoparticles (AgNPs). This method was chosen to obtain an Ag/SiO2 composite with nano size and high purity. AgNPs were synthesized using silver nitrate (AgNO3) by reduction method at 90 °C. The reducing agent and stabilizer used is trisodium citrate. UV-Vis, FTIR, XRD, and SEM-EDX were used for the analysis Ag/SiO2 composites. Uv-Vis analysis results Ag/SiO2 has an absorption peak at a wavelength of 412 nm with a bandgap energy of 2.25 eV. These peaks indicate that AgNPs have formed in the SiO2 membrane. The FTIR results revealed the Si-O-Si bonds which indicated the presence of silica and the Ag-O functional group, and the presence of AgNPs. The results of XRD analysis showed that the silica structure formed was cristobalite and silver crystals in the face center cubic (fcc) shape. The results of the SEM-EDX morphological analysis showed that the Ag/SiO2 nanocomposite was shaped like sharp stone chips and the presence of small granules (granules) with different particle sizes and shapes, slightly porous and the composition of the compounds in the Ag/SiO2 nanocomposite indicated the presence of various chemical elements in the sample, including carbon, oxygen, sodium, silica, and silver.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"87 1","pages":"31 - 42"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74591046","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}
Cellulose acetate (CA) composite membranes are tailored for potential gas-transportation and antibacterial activity by incorporating various ratios (0-8wt. %) of zeolite-CuO (10:1, ZC) composite. The aim behind this is to develop an anti-biofouling membrane with enhanced CO2 permeation and selection properties. In situ coprecipitation route is adopted to synthesize ZC that imparted morphological, structural, thermal, and performance characteristics of membranes synthesized by solution casting mechanism. FESEM analysis revealed, pores size transformed from 1µm to 1.4 nm as observed in M0 (virgin) and M4 (8wt. % ZC) membranes, respectively. The existence and linkages of impregnated ZC in the developed membranes are verified by FTIR investigations. TGA-tested thermally endured membranes are tested for gas permeation/selectivity. In comparison to virgin CA membrane, three folds enhancements in CO2 permeation and two folds in CO2/N2 selectivity are observed. Membranes are also evaluated for antibacterial test against ‘gram-negative bacteria’ elucidates that increasing ZC content in composite membranes exhibit remarkable results.
{"title":"Tailoring Zeolite-Composite (ZC) Impregnated Thermally Endured Nonporous Cellulose Acetate Membranes for Potential Gas Separation and Antibacterial Performances","authors":"Zainab Fatima, Amina Afzal, Sakeena Arshad","doi":"10.4028/p-c80drd","DOIUrl":"https://doi.org/10.4028/p-c80drd","url":null,"abstract":"Cellulose acetate (CA) composite membranes are tailored for potential gas-transportation and antibacterial activity by incorporating various ratios (0-8wt. %) of zeolite-CuO (10:1, ZC) composite. The aim behind this is to develop an anti-biofouling membrane with enhanced CO2 permeation and selection properties. In situ coprecipitation route is adopted to synthesize ZC that imparted morphological, structural, thermal, and performance characteristics of membranes synthesized by solution casting mechanism. FESEM analysis revealed, pores size transformed from 1µm to 1.4 nm as observed in M0 (virgin) and M4 (8wt. % ZC) membranes, respectively. The existence and linkages of impregnated ZC in the developed membranes are verified by FTIR investigations. TGA-tested thermally endured membranes are tested for gas permeation/selectivity. In comparison to virgin CA membrane, three folds enhancements in CO2 permeation and two folds in CO2/N2 selectivity are observed. Membranes are also evaluated for antibacterial test against ‘gram-negative bacteria’ elucidates that increasing ZC content in composite membranes exhibit remarkable results.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"17 1","pages":"43 - 58"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75276130","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}
A. Younes, A. Bouamer, Rachid Amraoui, N. Metidji, Mounia Guessoum, A. Abada
Nanostructured FeNi and FeNiGr alloys were successfully synthesized by the mechanical alloying technique. The alloys formation and different magnetic properties were studied as a function of milling time in the range of 0 to 30h by X-ray diffraction (XRD) technique, Scanning Electron Microscope (SEM) analysis and a Vibrating Sample Magnetometer (VSM) process. The X-ray diffraction study confirmed the apparition of the α-FeNi alloy after 5h of milling with an average crystallite size of 26.80nm. The crystallite size obtained after 30h of milling is 10.13nm, While, the lattice deformation increases from 0.431 to 0.935%. in addition, the analysis of the magnetization curves of the Fe-Ni alloys revealed original magnetic properties: super paramagnetic behavior, and especially saturation magnetization and significant coercivity. Furthermore, the addition of graphene into FeNi alloy, reduced its crystallite size from 11.56 to 6.65 nm, and increases the lattice strain and lattice parameter from 0.631 to 0.748% and from 0.28686 to 0.28704nm, respectively. Which, enhanced these magnetic properties, by increasing its coercivity (Hc) from 16. 07 to 135.42 Oe and Mr from 1.73 to 5.87 emu/g, while the magnetization saturation is decreased from 153.25 to 123.06 emu/g.
{"title":"Magnetic and Structural Properties of Fe-Ni and Fe-Ni-Gr Based Nanostructured Alloys Synthesized by Mechanical Alloying","authors":"A. Younes, A. Bouamer, Rachid Amraoui, N. Metidji, Mounia Guessoum, A. Abada","doi":"10.4028/p-5h903c","DOIUrl":"https://doi.org/10.4028/p-5h903c","url":null,"abstract":"Nanostructured FeNi and FeNiGr alloys were successfully synthesized by the mechanical alloying technique. The alloys formation and different magnetic properties were studied as a function of milling time in the range of 0 to 30h by X-ray diffraction (XRD) technique, Scanning Electron Microscope (SEM) analysis and a Vibrating Sample Magnetometer (VSM) process. The X-ray diffraction study confirmed the apparition of the α-FeNi alloy after 5h of milling with an average crystallite size of 26.80nm. The crystallite size obtained after 30h of milling is 10.13nm, While, the lattice deformation increases from 0.431 to 0.935%. in addition, the analysis of the magnetization curves of the Fe-Ni alloys revealed original magnetic properties: super paramagnetic behavior, and especially saturation magnetization and significant coercivity. Furthermore, the addition of graphene into FeNi alloy, reduced its crystallite size from 11.56 to 6.65 nm, and increases the lattice strain and lattice parameter from 0.631 to 0.748% and from 0.28686 to 0.28704nm, respectively. Which, enhanced these magnetic properties, by increasing its coercivity (Hc) from 16. 07 to 135.42 Oe and Mr from 1.73 to 5.87 emu/g, while the magnetization saturation is decreased from 153.25 to 123.06 emu/g.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"81 1","pages":"1 - 16"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90774879","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}
Zeeshan Abdullah, A. W. Anwar, I. Haq, Zunair Arslan, Asifa Mubashar, S. Ahmad, Abdul Waheed, M. Ajmal, Imrza Imran Aziz Baig
The ultrafine fibers of Poly Vinyl Alcohol (PVA) /Graphene Oxide (GO) composite were prepared by using a homemade electrospinning set-up at 12.5 kV and 12 cm with different concentrations of GO (1g/L, 0.75g/L, and 0.5g/L) in PVA. The effect of GO concentrations in 10% PVA solution on the diameter of fibers was investigated. Fourier Transform Infrared (FTIR) Spectroscopy was used to analyze the functional groups. Ultraviolet (UV)-visible spectra of GO suspension showed the absorption peak at 232 nm. The morphology of the nanofibers was analyzed by Scanning Electron Microscopy (SEM). The X-ray diffraction (XRD) technique was used to analyze the crystalline nature of this material. The diameter of nanofibers decreased with improved crystallinity, thus, increasing the concentration of GO in PVA.
{"title":"Synthesis of Graphene Oxide/ Poly(Vinyl Alcohol) Composite and Investigation of Graphene Oxide Effect on Diameter and Pore Size of Poly(Vinyl Alcohol) Nanofibers","authors":"Zeeshan Abdullah, A. W. Anwar, I. Haq, Zunair Arslan, Asifa Mubashar, S. Ahmad, Abdul Waheed, M. Ajmal, Imrza Imran Aziz Baig","doi":"10.4028/p-y1y1ln","DOIUrl":"https://doi.org/10.4028/p-y1y1ln","url":null,"abstract":"The ultrafine fibers of Poly Vinyl Alcohol (PVA) /Graphene Oxide (GO) composite were prepared by using a homemade electrospinning set-up at 12.5 kV and 12 cm with different concentrations of GO (1g/L, 0.75g/L, and 0.5g/L) in PVA. The effect of GO concentrations in 10% PVA solution on the diameter of fibers was investigated. Fourier Transform Infrared (FTIR) Spectroscopy was used to analyze the functional groups. Ultraviolet (UV)-visible spectra of GO suspension showed the absorption peak at 232 nm. The morphology of the nanofibers was analyzed by Scanning Electron Microscopy (SEM). The X-ray diffraction (XRD) technique was used to analyze the crystalline nature of this material. The diameter of nanofibers decreased with improved crystallinity, thus, increasing the concentration of GO in PVA.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"1 1","pages":"23 - 30"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88784140","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}
Herein, we report for the first time the thermal diffusivity of zinc ferrite/ silver/ silver chloride nanocomposite with a four-fold enhancement in comparison with the base fluid. A systematic analysis of the dependence of calcination temperature and synthesis routes on the crystallinity of nanocomposites of zinc ferrite with silver and silver chloride suiting it for diverse applications was done. Synthesized via the co-precipitation method, the samples were characterized using X-ray diffraction, Field emission scanning electron microscopy, Energy dispersive X-ray, Vibration sample magnetometer, ultraviolet-visible Diffusive Reflective spectroscopy and Photoluminescence studies. A zeta potential of -31.1mV was obtained for the sample showing good colloidal stability. The thermal diffusivity of the samples as nanofluids was analyzed using the dual beam thermal lens method. The study also envisages the magnetically retrievable and visible light-active nature of the synthesized samples indicating their suitability for photocatalytic degradation of toxic dyes. The work on photocatalytic degradation of methylene blue stands out in attaining rapid, efficient dye degradation of 98% within 90 minutes of sunlight exposure in comparison with unblended zinc ferrite nanoparticles even without any oxidizing agent.
{"title":"Enhanced Thermal Diffusivity and Photocatalytic Dye Degradation Capability of Zinc Ferrite/Silver/Silver Chloride Nanocomposites","authors":"Minu Pius, Frincy Francis, S. Joseph","doi":"10.4028/p-383q35","DOIUrl":"https://doi.org/10.4028/p-383q35","url":null,"abstract":"Herein, we report for the first time the thermal diffusivity of zinc ferrite/ silver/ silver chloride nanocomposite with a four-fold enhancement in comparison with the base fluid. A systematic analysis of the dependence of calcination temperature and synthesis routes on the crystallinity of nanocomposites of zinc ferrite with silver and silver chloride suiting it for diverse applications was done. Synthesized via the co-precipitation method, the samples were characterized using X-ray diffraction, Field emission scanning electron microscopy, Energy dispersive X-ray, Vibration sample magnetometer, ultraviolet-visible Diffusive Reflective spectroscopy and Photoluminescence studies. A zeta potential of -31.1mV was obtained for the sample showing good colloidal stability. The thermal diffusivity of the samples as nanofluids was analyzed using the dual beam thermal lens method. The study also envisages the magnetically retrievable and visible light-active nature of the synthesized samples indicating their suitability for photocatalytic degradation of toxic dyes. The work on photocatalytic degradation of methylene blue stands out in attaining rapid, efficient dye degradation of 98% within 90 minutes of sunlight exposure in comparison with unblended zinc ferrite nanoparticles even without any oxidizing agent.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"32 1","pages":"59 - 72"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85385655","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}
J. Mazurenko, L. Kaykan, Antony Żywczak, V. Kotsyubynsky, V. Boychuk, Lilia Turovska, I. Vakaliuk
This paper reports on the successful synthesis of fine nanoparticles of nickel-substituted lithium-iron ferrites of composition Li0.5-x/2NixFe2.5-x/2O4 (0.2≤ x ≤1.0) by the sol-gel autocombustion method. It has been found that the alternating current (AC) and direct current (DC) conductivity is preferably tuned due to its dependence on temperature and nickel doping. Analysis of the Arrhenius dependences also confirms the appearance of more than one conduction mechanism upon substitution. The predominance of one type of conductivity over another depends on the concentration of the substituting element. Measurement of the magnetic properties has shown that the substitution of Ni2+ can significantly change the saturation and residual magnetization. Samples of composition Li0.4Ni0.2Fe2.4O4 have the highest saturation magnetization (84.08 emu/g), residual magnetization (15.85 emu/g), and the lowest coercive force (0.18 kOe). All the obtained results indicate a significant effect of the substitution of Ni2+ ions on the structure and properties of Li0.5-x/2NixFe2.5-x/2O4 ferrite nanoparticles.Photocatalytic properties have been obtained by the degradation of Methylene Blue dye under illumination with a halogen lamp. It is shown that an increase in the content of nickel ions leads to a change in the type of conductivity: from n-type (unsubstituted lithium pentaferrite) to p-type (with substitution x = 0.8 and higher). These systems are characterized by hopping conduction realized by octa-positions according to the mechanisms Fe3++e-↔Fe2+, and Ni3+↔Ni2++h+. The predominance of one or another mechanism depends on the content of nickel ions. The optical band gap ranges from 1.4 to 2.25 eV. Samples with nickel content x = 0.4 and x = 0.8 have shown the best degradation ability, which is 97% within 160 min for Methylene Blue.
{"title":"Effect of Nickel Ions Substitution on the Magnetic and Optical Properties of a Nanosized Lithium-Iron Ferrite","authors":"J. Mazurenko, L. Kaykan, Antony Żywczak, V. Kotsyubynsky, V. Boychuk, Lilia Turovska, I. Vakaliuk","doi":"10.4028/p-l3c1ie","DOIUrl":"https://doi.org/10.4028/p-l3c1ie","url":null,"abstract":"This paper reports on the successful synthesis of fine nanoparticles of nickel-substituted lithium-iron ferrites of composition Li0.5-x/2NixFe2.5-x/2O4 (0.2≤ x ≤1.0) by the sol-gel autocombustion method. It has been found that the alternating current (AC) and direct current (DC) conductivity is preferably tuned due to its dependence on temperature and nickel doping. Analysis of the Arrhenius dependences also confirms the appearance of more than one conduction mechanism upon substitution. The predominance of one type of conductivity over another depends on the concentration of the substituting element. Measurement of the magnetic properties has shown that the substitution of Ni2+ can significantly change the saturation and residual magnetization. Samples of composition Li0.4Ni0.2Fe2.4O4 have the highest saturation magnetization (84.08 emu/g), residual magnetization (15.85 emu/g), and the lowest coercive force (0.18 kOe). All the obtained results indicate a significant effect of the substitution of Ni2+ ions on the structure and properties of Li0.5-x/2NixFe2.5-x/2O4 ferrite nanoparticles.Photocatalytic properties have been obtained by the degradation of Methylene Blue dye under illumination with a halogen lamp. It is shown that an increase in the content of nickel ions leads to a change in the type of conductivity: from n-type (unsubstituted lithium pentaferrite) to p-type (with substitution x = 0.8 and higher). These systems are characterized by hopping conduction realized by octa-positions according to the mechanisms Fe3++e-↔Fe2+, and Ni3+↔Ni2++h+. The predominance of one or another mechanism depends on the content of nickel ions. The optical band gap ranges from 1.4 to 2.25 eV. Samples with nickel content x = 0.4 and x = 0.8 have shown the best degradation ability, which is 97% within 160 min for Methylene Blue.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"26 1","pages":"73 - 90"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80049561","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}
J. Szűcsová, A. Zeleňáková, Ľuboš Nagy, Michael Barutiak, Eva Beňová, V. Zeleňák, V. Závisová
Magnetic-bead separation or purification serves as a technique for effective isolation of biomolecules. In presented work we prepared and characterized core-shell magnetic nanoparticle samples consisted of Fe3O4 core coated with SiO2 shell. Samples were subsequently coated with ligands MPTMS (3-(mercaptopropyl)trimethoxysilane), CPTMS (3-(chloropropyl)trimethoxysilane) and MMSP (3-(trimethoxysilyl)propyl methacrylate) with aim to increase the number of active centers for specific binding with RNA. Such samples were further investigated for their magnetic properties, size, and morphology. Magnetic properties were studied in DC field up to 5 T in temperature range 5 – 300 K. Size and morphology were determined from SEM micrographs and elemental compositions of the samples were investigated using EDX analysis. Modification of nanoparticle surface with different ligands leads to modification of active centers on the SiO2 surface on which the DNA and RNA molecules can be bounded. It also causes the change in magnetic and structural properties of nanoparticles.
{"title":"Influence of Ligands on Physicochemical Characteristics of Magnetic Nanoparticles","authors":"J. Szűcsová, A. Zeleňáková, Ľuboš Nagy, Michael Barutiak, Eva Beňová, V. Zeleňák, V. Závisová","doi":"10.4028/p-2x4090","DOIUrl":"https://doi.org/10.4028/p-2x4090","url":null,"abstract":"Magnetic-bead separation or purification serves as a technique for effective isolation of biomolecules. In presented work we prepared and characterized core-shell magnetic nanoparticle samples consisted of Fe3O4 core coated with SiO2 shell. Samples were subsequently coated with ligands MPTMS (3-(mercaptopropyl)trimethoxysilane), CPTMS (3-(chloropropyl)trimethoxysilane) and MMSP (3-(trimethoxysilyl)propyl methacrylate) with aim to increase the number of active centers for specific binding with RNA. Such samples were further investigated for their magnetic properties, size, and morphology. Magnetic properties were studied in DC field up to 5 T in temperature range 5 – 300 K. Size and morphology were determined from SEM micrographs and elemental compositions of the samples were investigated using EDX analysis. Modification of nanoparticle surface with different ligands leads to modification of active centers on the SiO2 surface on which the DNA and RNA molecules can be bounded. It also causes the change in magnetic and structural properties of nanoparticles.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"74 1","pages":"91 - 96"},"PeriodicalIF":1.7,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88948887","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}
In the present work, the performance of monolithic perovskite solar cells (mPSCs) was evaluated with regard to the concentration of methylammonium iodide (MAI) perovskites. The five different perovskite layers were carried out using different ratios of MAI:PbI2, labelled as A0, A1, A2, A3, and A4 accordingly, with corresponding ratios of 1:1, 1.1:1, 1.2:1, 1.3:1, and 1.4:1. In this study mPSCs with a sandwich type structure of glass/FTO/compact (c)-TiO2/mesoporous (mp)-TiO2/mesoporous (mp)-ZrO2/carbon was fabricated for this purpose. The fabricated mPSCs films were fully characterized by X-ray diffraction, Raman spectra and Filed emission scanning electron microscopy (FE-SEM). The photovoltaic characteristics were measured under AM 1.5, It was found that power conversion efficiency (PCE) increased with the increasing the concentration of MAI:PbI2 perovskites, from 1:1 to 1.1:1M. The maximum PCE of 17.68% was achieved mPSCs with MAI:PbI2 (1.1:1) as compared to mPSCs with MAI:PbI2 (1:1) PCE of 15.2%.
{"title":"Optimal Enhancement of Power Conversion Efficiency of Monolithic Perovskite Solar Cells by Effect of Methylammonium (MAI)","authors":"Bhagavanreddy Thokala, Devarapalli Nagendra Prasad, Kumar Manoj","doi":"10.4028/p-9ci284","DOIUrl":"https://doi.org/10.4028/p-9ci284","url":null,"abstract":"In the present work, the performance of monolithic perovskite solar cells (mPSCs) was evaluated with regard to the concentration of methylammonium iodide (MAI) perovskites. The five different perovskite layers were carried out using different ratios of MAI:PbI2, labelled as A0, A1, A2, A3, and A4 accordingly, with corresponding ratios of 1:1, 1.1:1, 1.2:1, 1.3:1, and 1.4:1. In this study mPSCs with a sandwich type structure of glass/FTO/compact (c)-TiO2/mesoporous (mp)-TiO2/mesoporous (mp)-ZrO2/carbon was fabricated for this purpose. The fabricated mPSCs films were fully characterized by X-ray diffraction, Raman spectra and Filed emission scanning electron microscopy (FE-SEM). The photovoltaic characteristics were measured under AM 1.5, It was found that power conversion efficiency (PCE) increased with the increasing the concentration of MAI:PbI2 perovskites, from 1:1 to 1.1:1M. The maximum PCE of 17.68% was achieved mPSCs with MAI:PbI2 (1.1:1) as compared to mPSCs with MAI:PbI2 (1:1) PCE of 15.2%.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"76 1","pages":"135 - 143"},"PeriodicalIF":1.7,"publicationDate":"2023-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85747515","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}
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