This study provides the formation of semiconductor nanowires (NWs) with a singular facet and a curved end surface by the vapor-liquid-solid (VLS) process that is analyzed and explained in details. Given the evidence, it is confirmed that the wettability of a liquid catalyst droplet on a crystal surface and the contact angle between the droplet and crystal play an essential role in the VLS process of NWs development. It is shown that for the VLS mechanism, the formation of NWs depends on the reduction in activation barrier to crystallization caused by the release of surplus-free energy by a spheroidizing drop in the region of the triple junction during the process of lowering surface area. This decreases the necessary supersaturation for the development of NW vertex facets at a fixed growth rate. The source of the extra free energy that drives the catalyst droplet movement during the steady-state development of NWs is the droplet’s outer surface. During the formation of NWs, those angles of inclination of the lateral surface NWs and droplet contact are obtained at which the solid/vapor, solid/liquid, and liquid/vapor interfaces experience the smallest increase in free energy. The wetting hysteresis is demonstrated to occur at the vertex of NWs, and the contact angle of a catalyst droplet may be regarded as an independent and fully-fledged thermodynamic parameter of the system’s state.
{"title":"About Some Fundamental Aspects of the Growth Mechanism Vapor-Liquid-Solid Nanowires","authors":"V. Nebol’sin, N. Swaikat","doi":"10.1155/2023/7906045","DOIUrl":"https://doi.org/10.1155/2023/7906045","url":null,"abstract":"This study provides the formation of semiconductor nanowires (NWs) with a singular facet and a curved end surface by the vapor-liquid-solid (VLS) process that is analyzed and explained in details. Given the evidence, it is confirmed that the wettability of a liquid catalyst droplet on a crystal surface and the contact angle between the droplet and crystal play an essential role in the VLS process of NWs development. It is shown that for the VLS mechanism, the formation of NWs depends on the reduction in activation barrier to crystallization caused by the release of surplus-free energy by a spheroidizing drop in the region of the triple junction during the process of lowering surface area. This decreases the necessary supersaturation for the development of NW vertex facets at a fixed growth rate. The source of the extra free energy that drives the catalyst droplet movement during the steady-state development of NWs is the droplet’s outer surface. During the formation of NWs, those angles of inclination of the lateral surface NWs and droplet contact are obtained at which the solid/vapor, solid/liquid, and liquid/vapor interfaces experience the smallest increase in free energy. The wetting hysteresis is demonstrated to occur at the vertex of NWs, and the contact angle of a catalyst droplet may be regarded as an independent and fully-fledged thermodynamic parameter of the system’s state.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"1999 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82781368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bachir Yaou Balarabe, Maman Nasser Illiassou Oumarou, A. Koroney, Irédon Adjama, Abdoul Razak Ibrahim Baraze
The textile industry’s discharges have long been regarded as severe water pollution. The photocatalytic degradation of dyes using semiconductors is one of the crucial methods. The present study efficiently used the mechanical method to synthesize Iron oxide Nanoparticles. XRD, FT-IR, UV-Vis DRS, and Raman analyses were performed to analyze the structural and optical. From the data provided by XRD and Raman data, we believed that the as-synthesized Iron oxide was pure hematite (α-Fe2O3) with a hexagonal structure. Additionally, the EDS results show that the synthesized material is pure. By adjusting specific parameters, including the dye concentration, the catalyst dosage, the pH, and the oxidizing agent such as H2O2 and K2S2O8, the degradation of eosin yellowish using Fe2O3 as a photocatalyst has been discussed. Additionally, the kinetics of eosin yellowish degradation has been studied. A study was also conducted using Fe2O3 nanoparticles attached to polyurethane polymer (PU) to investigate its photocatalytic activity on methylene blue, methyl orange, and indigo carmine. In 30 minutes, nearly 90% of the dyes had degraded. The total organic carbon (TOC) analysis confirmed this result.
{"title":"Photo-Oxidation of Organic Dye by Fe2O3 Nanoparticles: Catalyst, Electron Acceptor, and Polyurethane Membrane (PU-Fe2O3) Effects","authors":"Bachir Yaou Balarabe, Maman Nasser Illiassou Oumarou, A. Koroney, Irédon Adjama, Abdoul Razak Ibrahim Baraze","doi":"10.1155/2023/1292762","DOIUrl":"https://doi.org/10.1155/2023/1292762","url":null,"abstract":"The textile industry’s discharges have long been regarded as severe water pollution. The photocatalytic degradation of dyes using semiconductors is one of the crucial methods. The present study efficiently used the mechanical method to synthesize Iron oxide Nanoparticles. XRD, FT-IR, UV-Vis DRS, and Raman analyses were performed to analyze the structural and optical. From the data provided by XRD and Raman data, we believed that the as-synthesized Iron oxide was pure hematite (α-Fe2O3) with a hexagonal structure. Additionally, the EDS results show that the synthesized material is pure. By adjusting specific parameters, including the dye concentration, the catalyst dosage, the pH, and the oxidizing agent such as H2O2 and K2S2O8, the degradation of eosin yellowish using Fe2O3 as a photocatalyst has been discussed. Additionally, the kinetics of eosin yellowish degradation has been studied. A study was also conducted using Fe2O3 nanoparticles attached to polyurethane polymer (PU) to investigate its photocatalytic activity on methylene blue, methyl orange, and indigo carmine. In 30 minutes, nearly 90% of the dyes had degraded. The total organic carbon (TOC) analysis confirmed this result.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"85 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80916177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Interfacial carrier transfer kinetics is critical to the efficiency and stability of perovskite solar cells. Herein, we measure the regeneration rate constant, absorption cross-section, reduction rate constant, and conductivity of hole transport layered perovskites using scanning electrochemical microscopy (SECM). The SECM feedback revealed that the regeneration rate constant, absorption cross-section, and reduction rate constant of the nickel oxide (NiO) layer perovskite layer are higher than those of the poly (3,4-ethyenedioxythiophene)-poly (styrenesulfonate) layered perovskite. Also, at a specific flux density ( J h v ), the value of the regeneration rate constant (keff) in both blue and red illuminations for the NiO/CH3NH3PbI3 film is significantly higher than in both PEDOT: PSS/CH3NH3PbI3 and FTO/CH3NH3PbI3 films. The difference in keff between layered and nonlayered perovskite conforms to the impact of the hole conducting layer on the charge transfer kinetics. According to the findings, SECM is a powerful approach for screening an appropriate hole transport layer for stable perovskite solar cells.
界面载流子转移动力学对钙钛矿太阳能电池的效率和稳定性至关重要。本文利用扫描电化学显微镜(SECM)测量了孔传输层状钙钛矿的再生速率常数、吸收截面、还原速率常数和电导率。SECM反馈结果表明，氧化镍(NiO)层状钙钛矿的再生速率常数、吸收截面和还原速率常数均高于聚(3,4-乙烯二氧噻吩)-聚苯乙烯磺酸层状钙钛矿。此外，在特定的磁通密度(J h v)下，NiO/CH3NH3PbI3薄膜在蓝色和红色光照下的再生速率常数(keff)均显著高于PEDOT: PSS/CH3NH3PbI3和FTO/CH3NH3PbI3薄膜。层状钙钛矿与非层状钙钛矿的热系数差异符合空穴导电层对电荷转移动力学的影响。根据研究结果，SECM是为稳定的钙钛矿太阳能电池筛选合适的空穴传输层的有力方法。
{"title":"Scanning Electrochemical Microscope Studies of Charge Transfer Kinetics at the Interface of the Perovskite/Hole Transport Layer","authors":"Getachew Alemu Anshebo, Ataklti Abraha Gebreyohanes, Bizuneh Gebremichael Difer, Teketel Alemu Anshebo","doi":"10.1155/2023/1844719","DOIUrl":"https://doi.org/10.1155/2023/1844719","url":null,"abstract":"Interfacial carrier transfer kinetics is critical to the efficiency and stability of perovskite solar cells. Herein, we measure the regeneration rate constant, absorption cross-section, reduction rate constant, and conductivity of hole transport layered perovskites using scanning electrochemical microscopy (SECM). The SECM feedback revealed that the regeneration rate constant, absorption cross-section, and reduction rate constant of the nickel oxide (NiO) layer perovskite layer are higher than those of the poly (3,4-ethyenedioxythiophene)-poly (styrenesulfonate) layered perovskite. Also, at a specific flux density (\u0000 \u0000 \u0000 \u0000 J\u0000 \u0000 \u0000 h\u0000 v\u0000 \u0000 \u0000 \u0000 ), the value of the regeneration rate constant (keff) in both blue and red illuminations for the NiO/CH3NH3PbI3 film is significantly higher than in both PEDOT: PSS/CH3NH3PbI3 and FTO/CH3NH3PbI3 films. The difference in keff between layered and nonlayered perovskite conforms to the impact of the hole conducting layer on the charge transfer kinetics. According to the findings, SECM is a powerful approach for screening an appropriate hole transport layer for stable perovskite solar cells.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"66 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81528632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Chuan, Muhammad Amirul Irfan Misnon, N. Alias, M. Tan
Moore’s law is approaching its limit due to various challenges, especially the size limit of the transistors. The International Roadmap for Devices and Systems (IRDS), the successor of International Technology Roadmap for Semiconductors (ITRS), has included 2D materials as an alternative approach for the More-than-Moore nanoelectronic applications. Among the 2D materials, graphene nanoribbons (GNRs) have been widely used as the alternative channel materials of field-effect transistors (FETs). In this paper, the impacts of physical scaling on the device performance of double-gate Schottky-barrier GNR FETs (DG-SB-GNRFETs) are investigated by using NanoTCAD ViDES simulation tool based on the tight-binding Hamiltonian and self-consistent solutions of 3D Poisson and Schrödinger equations with open boundary conditions within the nonequilibrium Green’s function formalism. The extracted device performance parameters include the subthreshold swing and on-to-off current ratio. The results suggest that the performances of DG-SB-GNRFETs are strongly dependent on their physical parameters, especially the widths of the GNRs.
{"title":"Device Performance of Double-Gate Schottky-Barrier Graphene Nanoribbon Field-Effect Transistors with Physical Scaling","authors":"M. Chuan, Muhammad Amirul Irfan Misnon, N. Alias, M. Tan","doi":"10.1155/2023/1709570","DOIUrl":"https://doi.org/10.1155/2023/1709570","url":null,"abstract":"Moore’s law is approaching its limit due to various challenges, especially the size limit of the transistors. The International Roadmap for Devices and Systems (IRDS), the successor of International Technology Roadmap for Semiconductors (ITRS), has included 2D materials as an alternative approach for the More-than-Moore nanoelectronic applications. Among the 2D materials, graphene nanoribbons (GNRs) have been widely used as the alternative channel materials of field-effect transistors (FETs). In this paper, the impacts of physical scaling on the device performance of double-gate Schottky-barrier GNR FETs (DG-SB-GNRFETs) are investigated by using NanoTCAD ViDES simulation tool based on the tight-binding Hamiltonian and self-consistent solutions of 3D Poisson and Schrödinger equations with open boundary conditions within the nonequilibrium Green’s function formalism. The extracted device performance parameters include the subthreshold swing and on-to-off current ratio. The results suggest that the performances of DG-SB-GNRFETs are strongly dependent on their physical parameters, especially the widths of the GNRs.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"34 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81048407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Safaei, H. Moradpoor, Mohammad Salmani Mobarakeh, Nima Fallahnia
Developing novel antibacterial chemicals is constantly necessary since bacterial resistance to antibiotics is an inevitable occurrence. This research aimed to find the ideal conditions for using antibacterial zirconia (ZrO2) NPs with polymer alginate nanocomposites. Using the Taguchi method, alginate biopolymer, zirconia NPs, and stirring time were utilized to construct nine nanocomposites. Analysis of Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis), spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) indicated the development of nanocomposites with appropriate structural properties. Antibacterial efficacy against Streptococcus mutans (S. mutans) biofilm was the highest when the nanocomposite was formed under the circumstances of experiment 6 (zirconia 8 mg/ml, alginate 70 mg/ml, and 40 min stirring time). Alginate/zirconia bionanocomposites generated using the in situ technique proved efficient against S. mutans. Nanoparticles have a high surface-to-volume ratio and surface energy, which can cause them to agglomerate and make their antimicrobial effectiveness problematic. Using zirconia nanoparticles in an alginate polymer matrix in the form of nanocomposite can increase the stability of nanoparticles. Due to the advantageous antibacterial qualities of this bionanocomposite, it can be utilized in various medical materials and dental appliances.
{"title":"Optimization of Antibacterial, Structures, and Thermal Properties of Alginate-ZrO2 Bionanocomposite by the Taguchi Method","authors":"M. Safaei, H. Moradpoor, Mohammad Salmani Mobarakeh, Nima Fallahnia","doi":"10.1155/2022/7406168","DOIUrl":"https://doi.org/10.1155/2022/7406168","url":null,"abstract":"Developing novel antibacterial chemicals is constantly necessary since bacterial resistance to antibiotics is an inevitable occurrence. This research aimed to find the ideal conditions for using antibacterial zirconia (ZrO2) NPs with polymer alginate nanocomposites. Using the Taguchi method, alginate biopolymer, zirconia NPs, and stirring time were utilized to construct nine nanocomposites. Analysis of Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible (UV-vis), spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and thermogravimetric analysis (TGA) indicated the development of nanocomposites with appropriate structural properties. Antibacterial efficacy against Streptococcus mutans (S. mutans) biofilm was the highest when the nanocomposite was formed under the circumstances of experiment 6 (zirconia 8 mg/ml, alginate 70 mg/ml, and 40 min stirring time). Alginate/zirconia bionanocomposites generated using the in situ technique proved efficient against S. mutans. Nanoparticles have a high surface-to-volume ratio and surface energy, which can cause them to agglomerate and make their antimicrobial effectiveness problematic. Using zirconia nanoparticles in an alginate polymer matrix in the form of nanocomposite can increase the stability of nanoparticles. Due to the advantageous antibacterial qualities of this bionanocomposite, it can be utilized in various medical materials and dental appliances.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"20 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2022-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72750067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ricardo Hernández Pérez, René Salgado Delgado, Alfredo Olarte Paredes, Areli Salgado Delgado, Edgar García Hernández, Atenas Medrano Valis, Fryda Martínez Candia
Agroindustrial residues represent a serious environmental problem in the world; in this case, the polluting rice husk, present in the rice fields of Morelos State, is one source of incalculable biomass. The aim of this study was to assess two viable and optimized procedures for obtaining nanocellulose from these wastes. The sieved samples included 4 treatments with different grain sizes (sieves # 10, 15, 30, and 50) and three replicates. They were then processed by an alkaline treatment (NaOH) 5%, bleaching with sodium hypochlorite, followed by pretreatment with 0.65% hydrochloric acid (HCl). After drying, the cellulose was subjected to acid hydrolysis with (H2SO4) at 64%, and was compared to an enzymatic hydrolysis complex. This complex was formed of D-(+) cellobiose and endo-1,4-β-D-glucanase from Acidothermus cellulolyticus. End products were sonicated and dialyzed until they reach a neutral pH. Finally, the nanocellulose was characterized by FTIR, DSC, XRD, SEM, and TEM. Evident results recognize the nanocellulose (NC) synthesis by both routes, with greater contaminants generated in the medium by the acid hydrolysis. It is much more feasible and faster to achieve with enzymatic hydrolysis, less aggressive for the environment, and higher performance. In future trials, the cost-benefit of using the enzyme complex should be assessed as an alternative to replace acid hydrolysis.Key words: acid hydrolysis, enzymatic hydrolysis, waste, rice husk, Oryzasativa L, cellulose nanocrystals (CNCs).
{"title":"Comparing Acid and Enzymatic Hydrolysis Methods for Cellulose Nanocrystals (CNCs) Obtention from Agroindustrial Rice Husk Waste","authors":"Ricardo Hernández Pérez, René Salgado Delgado, Alfredo Olarte Paredes, Areli Salgado Delgado, Edgar García Hernández, Atenas Medrano Valis, Fryda Martínez Candia","doi":"10.1155/2022/5882113","DOIUrl":"https://doi.org/10.1155/2022/5882113","url":null,"abstract":"Agroindustrial residues represent a serious environmental problem in the world; in this case, the polluting rice husk, present in the rice fields of Morelos State, is one source of incalculable biomass. The aim of this study was to assess two viable and optimized procedures for obtaining nanocellulose from these wastes. The sieved samples included 4 treatments with different grain sizes (sieves # 10, 15, 30, and 50) and three replicates. They were then processed by an alkaline treatment (NaOH) 5%, bleaching with sodium hypochlorite, followed by pretreatment with 0.65% hydrochloric acid (HCl). After drying, the cellulose was subjected to acid hydrolysis with (H2SO4) at 64%, and was compared to an enzymatic hydrolysis complex. This complex was formed of D-(+) cellobiose and endo-1,4-β-D-glucanase from Acidothermus cellulolyticus. End products were sonicated and dialyzed until they reach a neutral pH. Finally, the nanocellulose was characterized by FTIR, DSC, XRD, SEM, and TEM. Evident results recognize the nanocellulose (NC) synthesis by both routes, with greater contaminants generated in the medium by the acid hydrolysis. It is much more feasible and faster to achieve with enzymatic hydrolysis, less aggressive for the environment, and higher performance. In future trials, the cost-benefit of using the enzyme complex should be assessed as an alternative to replace acid hydrolysis.Key words: acid hydrolysis, enzymatic hydrolysis, waste, rice husk, Oryzasativa L, cellulose nanocrystals (CNCs).","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"30 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2022-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87364686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bone defects and disorders include trauma, osteonecrosis, osteoporosis, bone tumours, arthritis rheumatoid, osteosarcoma, and iatrogenic injury. Obtaining a composite material with characteristics that mimic what bones in the human body have is a vital target for the purpose of replacing or repairing damaged bones. The key objective of this study was to develop a composite having mechanical and biological properties that resemble to a large extent native bone features. Highly biocompatible epoxy resin was reinforced by various weight fractions of seashell nanoparticles. The morphologies of the pristine bioepoxy, seashell-bioepoxy, and hydroxyapatite-bioepoxy composites were observed by scanning electron microscopy. Moreover, the mechanical properties were examined by the means of tension and Izod impact tests. Besides, the influence of seashell and hydroxyapatite nanoparticles on the bioepoxy chemical structure and thermal properties was also evaluated using Fourier transform infrared spectroscopy and differential scanning calorimetry technique, respectively. The tensile strength, modulus of elasticity, and impact strength of the seashell nanoparticle-reinforced bioepoxy were revealed to be higher than those of the unmodified bioepoxy and were significantly depended on the filler content. When the mass fraction of the reinforcement was 7 wt%, the improvement in the tensile strength, modulus of elasticity, and impact strength was around 46.7%, 37%, and 57%, respectively, compared to that of blank bioepoxy. In addition, these properties were higher for the composites loaded with seashell nanoparticles than those filled with commercially available hydroxyapatite nanoparticles. An enhancement in glass transition temperature for the bioepoxy after modification with both of these nanofillers was also achieved. All these features make these kinds of composites a promising option that could be used in the orthopaedic field. Furthermore, the use of seashell nanoparticles may reduce the cost of the resulted composite and alleviate the negative consequences of large quantity by-product waste seashells on the environment.
{"title":"Performance of Biocomposite Materials Reinforced by Hydroxyapatite and Seashell Nanoparticles for Bone Replacement","authors":"A. Hadi, M. R. Mohammed","doi":"10.1155/2022/9156522","DOIUrl":"https://doi.org/10.1155/2022/9156522","url":null,"abstract":"Bone defects and disorders include trauma, osteonecrosis, osteoporosis, bone tumours, arthritis rheumatoid, osteosarcoma, and iatrogenic injury. Obtaining a composite material with characteristics that mimic what bones in the human body have is a vital target for the purpose of replacing or repairing damaged bones. The key objective of this study was to develop a composite having mechanical and biological properties that resemble to a large extent native bone features. Highly biocompatible epoxy resin was reinforced by various weight fractions of seashell nanoparticles. The morphologies of the pristine bioepoxy, seashell-bioepoxy, and hydroxyapatite-bioepoxy composites were observed by scanning electron microscopy. Moreover, the mechanical properties were examined by the means of tension and Izod impact tests. Besides, the influence of seashell and hydroxyapatite nanoparticles on the bioepoxy chemical structure and thermal properties was also evaluated using Fourier transform infrared spectroscopy and differential scanning calorimetry technique, respectively. The tensile strength, modulus of elasticity, and impact strength of the seashell nanoparticle-reinforced bioepoxy were revealed to be higher than those of the unmodified bioepoxy and were significantly depended on the filler content. When the mass fraction of the reinforcement was 7 wt%, the improvement in the tensile strength, modulus of elasticity, and impact strength was around 46.7%, 37%, and 57%, respectively, compared to that of blank bioepoxy. In addition, these properties were higher for the composites loaded with seashell nanoparticles than those filled with commercially available hydroxyapatite nanoparticles. An enhancement in glass transition temperature for the bioepoxy after modification with both of these nanofillers was also achieved. All these features make these kinds of composites a promising option that could be used in the orthopaedic field. Furthermore, the use of seashell nanoparticles may reduce the cost of the resulted composite and alleviate the negative consequences of large quantity by-product waste seashells on the environment.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"16 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2022-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88939648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sizwe Ngcobo, B. Silwana, Kanyisa Maqhashu, M. Matoetoe
This study assesses the physical and electrochemical changes of bimetallic Ag-Au nanoparticle-functionalized bentonite nanoclay. Nanoclay was studied to deduce a better sensing material/film. A chemical co-reduction method was used to synthesize bimetallic Ag-Au c nanoparticles, which were used to prepare a Ag-Au/PGV bentonite composite. Bimetallic Ag-AuNPs and their nanoclay composite were optically characterized using the scanning electron microscope, ultraviolet visible spectroscopy, X-ray diffraction, and Fourier transform infrared, whilst cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to ascertain their electrochemical activity and properties. The results of surface morphological inspection showed an average size of 10 nm, in agreement with XRD. The bimetallic Ag-AuNPs UV/Vis characteristic wavelengths of 414 nm and 516 nm confirmed the presence of Ag and Au metals, respectively. XRD exhibited diffraction planes related to 2θ values of Ag and Au metals, whilst FTIR indicated mainly COO- functional groups from the citrate capping of bimetallic Ag-Au NPs. CV and DPV showed that bentonite nanoclay is largely insulated by silicates but exhibited a small electroactivity of Fe. The electroactivity of Ag-Au/PGV bentonite exhibited peak potentials due to Ag/Ag+ and Au/Au3+ redox couples at 0.19 V/−0.20 V and 1.37 V/0.42, respectively. The Ag-Au/PGV bentonite nanocomposite exhibited the highest surface concentration of 3.25 × 10−2 cm2, a diffusion coefficient of 2.36 × −11 cm2/s, and an electron transfer rate constant (Ks) of 1.99 × 10−4 cm2. The outcome of these results indicated that the Ag-Au/PGV bentonite nanocomposite was more electroactive than PGV. Therefore, this study accentuates Ag-Au/PGV bentonite nanocomposite as a novel and promising platform for electrochemical sensing with higher sensitivity and efficiency than other sensing materials.
{"title":"Bentonite Nanoclay Optoelectrochemical Property Improvement through Bimetallic Silver and Gold Nanoparticles","authors":"Sizwe Ngcobo, B. Silwana, Kanyisa Maqhashu, M. Matoetoe","doi":"10.1155/2022/3693938","DOIUrl":"https://doi.org/10.1155/2022/3693938","url":null,"abstract":"This study assesses the physical and electrochemical changes of bimetallic Ag-Au nanoparticle-functionalized bentonite nanoclay. Nanoclay was studied to deduce a better sensing material/film. A chemical co-reduction method was used to synthesize bimetallic Ag-Au c nanoparticles, which were used to prepare a Ag-Au/PGV bentonite composite. Bimetallic Ag-AuNPs and their nanoclay composite were optically characterized using the scanning electron microscope, ultraviolet visible spectroscopy, X-ray diffraction, and Fourier transform infrared, whilst cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to ascertain their electrochemical activity and properties. The results of surface morphological inspection showed an average size of 10 nm, in agreement with XRD. The bimetallic Ag-AuNPs UV/Vis characteristic wavelengths of 414 nm and 516 nm confirmed the presence of Ag and Au metals, respectively. XRD exhibited diffraction planes related to 2θ values of Ag and Au metals, whilst FTIR indicated mainly COO- functional groups from the citrate capping of bimetallic Ag-Au NPs. CV and DPV showed that bentonite nanoclay is largely insulated by silicates but exhibited a small electroactivity of Fe. The electroactivity of Ag-Au/PGV bentonite exhibited peak potentials due to Ag/Ag+ and Au/Au3+ redox couples at 0.19 V/−0.20 V and 1.37 V/0.42, respectively. The Ag-Au/PGV bentonite nanocomposite exhibited the highest surface concentration of 3.25 × 10−2 cm2, a diffusion coefficient of 2.36 × −11 cm2/s, and an electron transfer rate constant (Ks) of 1.99 × 10−4 cm2. The outcome of these results indicated that the Ag-Au/PGV bentonite nanocomposite was more electroactive than PGV. Therefore, this study accentuates Ag-Au/PGV bentonite nanocomposite as a novel and promising platform for electrochemical sensing with higher sensitivity and efficiency than other sensing materials.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"41 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2022-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86259490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shyam Sundar Gandi, S. Gandi, S. Parne, Motilal Lakavat, Nageswara Rao Lakkimsetty, G. Gedda
The hydrothermal treatment was used to create a natural hierarchical bio-inspired carbon and nitrogen-doped C/N/TiO2 hybrid composite. It is the goal of this work to investigate the photocatalytic activity of bio-inspired C/N/TiO2 hybrid composite. Techniques such as X-ray powder diffraction, scanning electron microscopy, UV-Vis absorption spectroscopy, FTIR, Raman, and photoluminescence spectroscopy were used to explore the structural, morphological, and photocatalysis characteristics of the bio-inspired C/N/TiO2 hybrid composite. By doping carbon and nitrogen, TiO2 nanotubes were able to improve the photocatalyst properties of the C/N/TiO2 hybrid composite, decrease the energy band gap (∼2.55 eV), and result in increased electron transfer efficiency when compared to pure TiO2. The photocatalytic degradation of pollutants (rhodamine B (RhB)) is made possible by the use of a bio-inspired C/N/TiO2 hybrid composite that has high interconnectivity and an easily accessible surface.
{"title":"Bio-Inspired C/N/TiO2 Hybrid Composite Heterostructure: Enhanced Photocatalytic Activity under Visible Light","authors":"Shyam Sundar Gandi, S. Gandi, S. Parne, Motilal Lakavat, Nageswara Rao Lakkimsetty, G. Gedda","doi":"10.1155/2022/5816063","DOIUrl":"https://doi.org/10.1155/2022/5816063","url":null,"abstract":"The hydrothermal treatment was used to create a natural hierarchical bio-inspired carbon and nitrogen-doped C/N/TiO2 hybrid composite. It is the goal of this work to investigate the photocatalytic activity of bio-inspired C/N/TiO2 hybrid composite. Techniques such as X-ray powder diffraction, scanning electron microscopy, UV-Vis absorption spectroscopy, FTIR, Raman, and photoluminescence spectroscopy were used to explore the structural, morphological, and photocatalysis characteristics of the bio-inspired C/N/TiO2 hybrid composite. By doping carbon and nitrogen, TiO2 nanotubes were able to improve the photocatalyst properties of the C/N/TiO2 hybrid composite, decrease the energy band gap (∼2.55 eV), and result in increased electron transfer efficiency when compared to pure TiO2. The photocatalytic degradation of pollutants (rhodamine B (RhB)) is made possible by the use of a bio-inspired C/N/TiO2 hybrid composite that has high interconnectivity and an easily accessible surface.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"17 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80064865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Mohamed, E. Fawzy, R. Shehab, M. Abdel-Salam, Rawheya A. Salah El Din, Hesham M. Abd El Fatah
A green, eco-friendly approach to biosynthesizing silver nanoparticles has been reported for marine macroalga (Cystoseira myrica) extract as a reducing agent. Different pH and temperature impact the green synthesis of silver nanoparticles suggesting that the synthesis depends greatly on pH and temperature. The structure and characters of synthesized nanoparticles were confirmed using HR-TEM, DLS, XRD, and FTIR. Cytotoxicity was indicated using provided cell lines of breast carcinoma cells (MCF-7) and human hepatocellular carcinoma cells (HepG2). Shape of silver nanoparticles at pH 9 and 75°C for 30 min was found to be suitable for the biosynthesis process and the AgNPs exhibited a characteristic absorption peak at 434 nm. High Resolution Electron Microscope Transmission reported polydisperse and spherical shapes ranging from 8 to 15 nm. High attractive and repulsive forces between each nanoparticle were recorded with an average zeta-potential value of approximately −29.3 mV. The X-ray diffraction study revealed the crystalline structure of silver nanoparticles. FTIR has shown the bioreduction of silver ions to silver nanoparticles through biomolecules found in algal extract. Silver nanoparticles have been found to have anticancer activity. The cytotoxicity assay was studied against MCF-7 and HepG2 at various concentrations (100, 50, 25, 12.5, 6.25, 3.125, 1.56, 0.78, 0.39, 0.2, and 0.1 μg/mL). By increasing the concentration of AgNPs from 0.1 to 100 μg/mL, the maximum percentage of viability against MCF-7 and HepG2 cell line decreased from 94.55 ± 7.55 to 19.879 ± 0.503 and from 78.56 ± 11.36 to 25.81 ± 2.66 after time exposure, respectively.
{"title":"Production, Characterization, and Cytotoxicity Effects of Silver Nanoparticles from Brown Alga (Cystoseira myrica)","authors":"R. Mohamed, E. Fawzy, R. Shehab, M. Abdel-Salam, Rawheya A. Salah El Din, Hesham M. Abd El Fatah","doi":"10.1155/2022/6469090","DOIUrl":"https://doi.org/10.1155/2022/6469090","url":null,"abstract":"A green, eco-friendly approach to biosynthesizing silver nanoparticles has been reported for marine macroalga (Cystoseira myrica) extract as a reducing agent. Different pH and temperature impact the green synthesis of silver nanoparticles suggesting that the synthesis depends greatly on pH and temperature. The structure and characters of synthesized nanoparticles were confirmed using HR-TEM, DLS, XRD, and FTIR. Cytotoxicity was indicated using provided cell lines of breast carcinoma cells (MCF-7) and human hepatocellular carcinoma cells (HepG2). Shape of silver nanoparticles at pH 9 and 75°C for 30 min was found to be suitable for the biosynthesis process and the AgNPs exhibited a characteristic absorption peak at 434 nm. High Resolution Electron Microscope Transmission reported polydisperse and spherical shapes ranging from 8 to 15 nm. High attractive and repulsive forces between each nanoparticle were recorded with an average zeta-potential value of approximately −29.3 mV. The X-ray diffraction study revealed the crystalline structure of silver nanoparticles. FTIR has shown the bioreduction of silver ions to silver nanoparticles through biomolecules found in algal extract. Silver nanoparticles have been found to have anticancer activity. The cytotoxicity assay was studied against MCF-7 and HepG2 at various concentrations (100, 50, 25, 12.5, 6.25, 3.125, 1.56, 0.78, 0.39, 0.2, and 0.1 μg/mL). By increasing the concentration of AgNPs from 0.1 to 100 μg/mL, the maximum percentage of viability against MCF-7 and HepG2 cell line decreased from 94.55 ± 7.55 to 19.879 ± 0.503 and from 78.56 ± 11.36 to 25.81 ± 2.66 after time exposure, respectively.","PeriodicalId":16378,"journal":{"name":"Journal of Nanotechnology","volume":"25 1","pages":""},"PeriodicalIF":4.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81391700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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