Graphene transistors are considered to be the successors’ of MOS transistors for the next generation of advanced integrated circuits. However, graphene suffers from the absence of energy band gap to experience a semiconductor like characteristics. In order to instigate a bandgap in graphene, several techniques and methods are introduced to beak its symmetry. The most common graphene form is the Graphene Nanoribbon (GNR) sheets. Few techniques have been used to grow GNR sheets. However, the main methods that gave better results are bottom-up techniques mainly based on nanotechnology principles. The present paper deals with the investigation of the bandgap engineering approach targeting an increase in graphene transistors switching characteristics leading to higher maximum frequencies applications. The GNR sheets are synthesized using bottom-up CVD based techniques yielding controlled electronics and physical characteristics. Results obtained on few GNR transistor samples compared to other forms of transistors showed good agreements and found to be close to that of standard silicon devices. Moreover, the GNRFETs frequency response is directly related to the bandgap of the material. It has been evidenced that gap modulation modulates the transistor frequency response. Whereas using other techniques, this cannot be achieved. We have found that small values of gap (100-300 meV) led to high mobility and frequencies of thousands of GHz. However, the edge quality limits the maximum frequencies as it induces traps in the graphene generated gap.
{"title":"Improving High Speed Switching Graphene Transistors Using Bandgap Engineering","authors":"A. Benfdila","doi":"10.4028/p-b3jg3k","DOIUrl":"https://doi.org/10.4028/p-b3jg3k","url":null,"abstract":"Graphene transistors are considered to be the successors’ of MOS transistors for the next generation of advanced integrated circuits. However, graphene suffers from the absence of energy band gap to experience a semiconductor like characteristics. In order to instigate a bandgap in graphene, several techniques and methods are introduced to beak its symmetry. The most common graphene form is the Graphene Nanoribbon (GNR) sheets. Few techniques have been used to grow GNR sheets. However, the main methods that gave better results are bottom-up techniques mainly based on nanotechnology principles. The present paper deals with the investigation of the bandgap engineering approach targeting an increase in graphene transistors switching characteristics leading to higher maximum frequencies applications. The GNR sheets are synthesized using bottom-up CVD based techniques yielding controlled electronics and physical characteristics. Results obtained on few GNR transistor samples compared to other forms of transistors showed good agreements and found to be close to that of standard silicon devices. Moreover, the GNRFETs frequency response is directly related to the bandgap of the material. It has been evidenced that gap modulation modulates the transistor frequency response. Whereas using other techniques, this cannot be achieved. We have found that small values of gap (100-300 meV) led to high mobility and frequencies of thousands of GHz. However, the edge quality limits the maximum frequencies as it induces traps in the graphene generated gap.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"44 1","pages":"113 - 122"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86189644","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}
Subhodeep Barman, J. Kumar, Arnab Das, Suranjan Sikdar, Abhijit Biswas, A. Srinivasan, Rahul Das
This article presents a comparative study between the ZnO nanocone and nanofibers. ZnO nanocones were synthesized through the green route, using Azadirachta indica leaf extract media, and ZnO nanofibers were synthesized by the electrospinning process. The microstructural parameters of the prepared nanomaterials were investigated using powder X-ray diffractometer (XRD) and Rietveld refinement analysis. The XRD patterns confirmed the formation of single-phase ZnO with hexagonal wurtzite structure having an average crystallite size of 21 nm and 54 nm for the conical and fibrous nanoparticles, respectively. The field emission scanning electron microscopy revealed that the mean radius of nanofibers was 25-30 nm while the mean height and mean base radius of nanocones were 181 nm and 91 nm respectively. Elastic properties were estimated using elastic compliances S11 (6.0678×10-12 m2N-1), S12 (-2.2602×10-12 m2N-1), S13 (-1.3579×10-12 m2N-1), S33 (5.5196×10-12 m2N-1) and S44 (22.6833×10-12 m2N-1) which were calculated using the THERMO-PW code, based on the density functional theory. The calculated elastic constants of the two nanostructures yielded similar values as expected. However, the elastic limit of the two nanostructures differs due to their morphological anomaly. Moreover, the optical bandgap of nanofibrous ZnO was lower than that of nanoconical ZnO.
{"title":"Comparative Study of ZnO Nanomaterials Synthesized by Green and Electrospinning Methods","authors":"Subhodeep Barman, J. Kumar, Arnab Das, Suranjan Sikdar, Abhijit Biswas, A. Srinivasan, Rahul Das","doi":"10.4028/p-vv17a6","DOIUrl":"https://doi.org/10.4028/p-vv17a6","url":null,"abstract":"This article presents a comparative study between the ZnO nanocone and nanofibers. ZnO nanocones were synthesized through the green route, using Azadirachta indica leaf extract media, and ZnO nanofibers were synthesized by the electrospinning process. The microstructural parameters of the prepared nanomaterials were investigated using powder X-ray diffractometer (XRD) and Rietveld refinement analysis. The XRD patterns confirmed the formation of single-phase ZnO with hexagonal wurtzite structure having an average crystallite size of 21 nm and 54 nm for the conical and fibrous nanoparticles, respectively. The field emission scanning electron microscopy revealed that the mean radius of nanofibers was 25-30 nm while the mean height and mean base radius of nanocones were 181 nm and 91 nm respectively. Elastic properties were estimated using elastic compliances S11 (6.0678×10-12 m2N-1), S12 (-2.2602×10-12 m2N-1), S13 (-1.3579×10-12 m2N-1), S33 (5.5196×10-12 m2N-1) and S44 (22.6833×10-12 m2N-1) which were calculated using the THERMO-PW code, based on the density functional theory. The calculated elastic constants of the two nanostructures yielded similar values as expected. However, the elastic limit of the two nanostructures differs due to their morphological anomaly. Moreover, the optical bandgap of nanofibrous ZnO was lower than that of nanoconical ZnO.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"14 1","pages":"81 - 93"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90895327","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}
The aim of this study was to investigate the possibility of the using UV irradiation on Graphene oxide (UV/GO) for the degradation of total organic carbon (TOC) from water. The experiments were carried out with various experimental conditions such as pH (3, 5 and 9), dosage of Graphene Oxide (GO)(0.2,0.4,0.6 and 0.8 g/L-1), concentration of Humic acid (HA)(0.5, 1, 1.5, 2 and 3 g/L), irradiation time (15, 30, 45 and 60 min) and UV intensity (4W and 8W) and optimized for the maximum removal of HA. The equilibrium adsorption data and the model parameters were evaluated. Based on the experimental data obtained in a lab-scale batch study, the theoretical efficiency of HA removal, under the optimum oxidation conditions (pH: 3, irradiation time: 45 min, catalyst dosage: 0.4g/L-1, UV: 8W and initial HA concentration: 3 g/L-1) was 71%. The isotherm study indicates that adsorption data fit well with the Langmuir model and Pseudo second-order kinetics. This study clearly indicated that GO/UV photo catalyst reactor is a cost effective and simple alternative method for degradation of HA from water.
{"title":"Photocatalytic Degradation of Total Organic Carbon in Water by under UV Irradiation on Graphene Oxide","authors":"L. Kalankesh, M. Zazouli","doi":"10.4028/p-0j6479","DOIUrl":"https://doi.org/10.4028/p-0j6479","url":null,"abstract":"The aim of this study was to investigate the possibility of the using UV irradiation on Graphene oxide (UV/GO) for the degradation of total organic carbon (TOC) from water. The experiments were carried out with various experimental conditions such as pH (3, 5 and 9), dosage of Graphene Oxide (GO)(0.2,0.4,0.6 and 0.8 g/L-1), concentration of Humic acid (HA)(0.5, 1, 1.5, 2 and 3 g/L), irradiation time (15, 30, 45 and 60 min) and UV intensity (4W and 8W) and optimized for the maximum removal of HA. The equilibrium adsorption data and the model parameters were evaluated. Based on the experimental data obtained in a lab-scale batch study, the theoretical efficiency of HA removal, under the optimum oxidation conditions (pH: 3, irradiation time: 45 min, catalyst dosage: 0.4g/L-1, UV: 8W and initial HA concentration: 3 g/L-1) was 71%. The isotherm study indicates that adsorption data fit well with the Langmuir model and Pseudo second-order kinetics. This study clearly indicated that GO/UV photo catalyst reactor is a cost effective and simple alternative method for degradation of HA from water.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"93 1","pages":"123 - 137"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76536682","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}
The properties of organic polymers implanted with low-energy ions are of scientific and practical interest. In this work, we consider the nanostructure produced in the near-surface region of polymethylmethacrylate (PMMA) implanted with silicon (Si+) ions at energy of 50 keV and ion fluence of 1016 ions/cm2. By controlled local chemical modification in a depth of 150 – 200 nm, in PMMA was created a nano-thin bi-layer configuration consisting of ion-modified layer and ion-implanted layer with carbonaceous nanostructure. Such complex nanoscale arrangement and organic transconductance configuration was characterized by direct current electrical measurements. The field-effect configuration in Si+-implanted PMMA was driven through the formed ion-implanted buried planar layer (as a channel with a thickness of about 100 nm) of nanoclustered amorphous carbon as an organic semiconductor. The values of performance parameters, such as the charge carrier mobility, contact resistance and gate leakage current of this particular type of organic field-effect transistor configuration were determined.
{"title":"Near-Surface Nanostructuring of Polymethylmethacrylate by Silicon Ion Implantation","authors":"G. Hadjichristov, T. Ivanov","doi":"10.4028/p-h6322i","DOIUrl":"https://doi.org/10.4028/p-h6322i","url":null,"abstract":"The properties of organic polymers implanted with low-energy ions are of scientific and practical interest. In this work, we consider the nanostructure produced in the near-surface region of polymethylmethacrylate (PMMA) implanted with silicon (Si+) ions at energy of 50 keV and ion fluence of 1016 ions/cm2. By controlled local chemical modification in a depth of 150 – 200 nm, in PMMA was created a nano-thin bi-layer configuration consisting of ion-modified layer and ion-implanted layer with carbonaceous nanostructure. Such complex nanoscale arrangement and organic transconductance configuration was characterized by direct current electrical measurements. The field-effect configuration in Si+-implanted PMMA was driven through the formed ion-implanted buried planar layer (as a channel with a thickness of about 100 nm) of nanoclustered amorphous carbon as an organic semiconductor. The values of performance parameters, such as the charge carrier mobility, contact resistance and gate leakage current of this particular type of organic field-effect transistor configuration were determined.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"72 1","pages":"95 - 112"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75944359","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}
Molecular dynamics simulation is used to study the water flow in a charged nanotube. The simulation results show that the charge patterns on the nanotube have an important role in determining the flow behavior. In a nanotube charged with one pattern, the water flow rate decreases with increasing charge value, when the charge value increases from 0 to 0.8 e, the water flow rate decreases to 7%. While in the other one with a different charge pattern, the water flow rate is independent of charge value. By analyzing the morphology of water molecules, it is determined that this unexpected phenomenon is caused by the structure of water molecules near the nanotube wall. For the first charge pattern, the network of hydrogen bonds formed by water molecules near the wall had a hexagonal structure, similar to single layer ice, which changes the interactions between the wall and the water molecules. By contrast, the second pattern did not exhibit such an effect. This study provides a means to control the rate of water flow in nanotubes using an electric field. These results may provide new insights and lead to new methods for flow control in complex micro- or nanofluidic systems.
{"title":"Controlling Water Flow in Pattern-Charged Nanotubes","authors":"R. Zhang, G. Du, Mei Fen Wang, Song Yuan Li","doi":"10.4028/p-29104k","DOIUrl":"https://doi.org/10.4028/p-29104k","url":null,"abstract":"Molecular dynamics simulation is used to study the water flow in a charged nanotube. The simulation results show that the charge patterns on the nanotube have an important role in determining the flow behavior. In a nanotube charged with one pattern, the water flow rate decreases with increasing charge value, when the charge value increases from 0 to 0.8 e, the water flow rate decreases to 7%. While in the other one with a different charge pattern, the water flow rate is independent of charge value. By analyzing the morphology of water molecules, it is determined that this unexpected phenomenon is caused by the structure of water molecules near the nanotube wall. For the first charge pattern, the network of hydrogen bonds formed by water molecules near the wall had a hexagonal structure, similar to single layer ice, which changes the interactions between the wall and the water molecules. By contrast, the second pattern did not exhibit such an effect. This study provides a means to control the rate of water flow in nanotubes using an electric field. These results may provide new insights and lead to new methods for flow control in complex micro- or nanofluidic systems.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"18 1","pages":"1 - 10"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90539109","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}
N. Pereira, J. Carballo, Marcos Daniel Vozer Felisberto, G. Silva
Graphene oxide and reduced graphene oxide films have widespread applications in many fields. There are several methods for preparing thin films of these materials in different substrates, but a method that offers low cost and high quality in thin-film fabrication is still lacking. Here, we report a low cost and easily scalable methodology to produce reduced graphene oxide conductive films in polyethylene terephthalate (PET) substrates from graphene oxide suspensions. In an environmentally friendly approach, the reduction process was carried out in a green chemistry fashion way using ascorbic acid as reduction agent. Graphene oxide was synthesized by modified Hummers' method and the coating was realized in a homemade dip-coating process. Films with light transmittance as high as 99% and surface resistance in the order of MΩ/sq were obtained with graphene oxide contents as low as 0.5 wt%. The increase in graphene oxide contents produced films with surface resistance as low as 13 kΩ/sq. These are very interesting results that allows these films to be considered for application in electromagnetic shielding and electrostatic dissipation.
{"title":"A Facile Production of Reduced Graphene Oxide Transparent Films in Polyethylene Terephthalate Substrates","authors":"N. Pereira, J. Carballo, Marcos Daniel Vozer Felisberto, G. Silva","doi":"10.4028/p-110q6p","DOIUrl":"https://doi.org/10.4028/p-110q6p","url":null,"abstract":"Graphene oxide and reduced graphene oxide films have widespread applications in many fields. There are several methods for preparing thin films of these materials in different substrates, but a method that offers low cost and high quality in thin-film fabrication is still lacking. Here, we report a low cost and easily scalable methodology to produce reduced graphene oxide conductive films in polyethylene terephthalate (PET) substrates from graphene oxide suspensions. In an environmentally friendly approach, the reduction process was carried out in a green chemistry fashion way using ascorbic acid as reduction agent. Graphene oxide was synthesized by modified Hummers' method and the coating was realized in a homemade dip-coating process. Films with light transmittance as high as 99% and surface resistance in the order of MΩ/sq were obtained with graphene oxide contents as low as 0.5 wt%. The increase in graphene oxide contents produced films with surface resistance as low as 13 kΩ/sq. These are very interesting results that allows these films to be considered for application in electromagnetic shielding and electrostatic dissipation.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"25 1","pages":"53 - 65"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81219567","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}
Hadjer Rekkache, Houda Kassentini, L. Bechiri, N. Benslim, A. Amara, X. Portier, P. Marie
Nanoparticles Cu2SnSe3 alloys were synthesized by mechanical alloying from mixtures of pure crystalline Cu, Sn and Se powders using a low cost planetary ball milling process optimizing the milling duration and the rotational speed. The properties of Cu2SnSe3 (CTSe) thin films deposited by thermal evaporation from this powder on glass substrate at Ts = 400°C were investigated. Powders and films were analyzed by X-ray diffraction (XRD), scanning electron microscopy(SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), to determine their microstructure, morphology, chemical compositions and root-mean-square (RMS) roughness. XRD analysis revealed that all samples crystallize in polycrystalline nature with cubic structure and lattice parameter a = 5.68 Å. The optical measurements were carried out in the [500-2500nm] wavelength range and were determined from spectral transmission data. Optical measurements showed that the deposited layers had a relatively high absorption coefficient of 104 cm-1 and the direct energy band gap was found to be around Eg =1.29eV. The suitable p-type conductivity of CTSe thin films was confirmed by hot probe method. Other electrical parameters (carrier concentration np = 10.04x1018 cm-3, electrical resistivity ρ = 30.49x10-2 Ω cm and mobility μH = 94.33 cm2/V s) were measured at room temperature.
{"title":"Study of Copper Tin Selenide Nanoparticles of Milled Powder and Thin Films","authors":"Hadjer Rekkache, Houda Kassentini, L. Bechiri, N. Benslim, A. Amara, X. Portier, P. Marie","doi":"10.4028/p-0069ke","DOIUrl":"https://doi.org/10.4028/p-0069ke","url":null,"abstract":"Nanoparticles Cu2SnSe3 alloys were synthesized by mechanical alloying from mixtures of pure crystalline Cu, Sn and Se powders using a low cost planetary ball milling process optimizing the milling duration and the rotational speed. The properties of Cu2SnSe3 (CTSe) thin films deposited by thermal evaporation from this powder on glass substrate at Ts = 400°C were investigated. Powders and films were analyzed by X-ray diffraction (XRD), scanning electron microscopy(SEM), energy dispersive X-ray analysis (EDX), atomic force microscopy (AFM), to determine their microstructure, morphology, chemical compositions and root-mean-square (RMS) roughness. XRD analysis revealed that all samples crystallize in polycrystalline nature with cubic structure and lattice parameter a = 5.68 Å. The optical measurements were carried out in the [500-2500nm] wavelength range and were determined from spectral transmission data. Optical measurements showed that the deposited layers had a relatively high absorption coefficient of 104 cm-1 and the direct energy band gap was found to be around Eg =1.29eV. The suitable p-type conductivity of CTSe thin films was confirmed by hot probe method. Other electrical parameters (carrier concentration np = 10.04x1018 cm-3, electrical resistivity ρ = 30.49x10-2 Ω cm and mobility μH = 94.33 cm2/V s) were measured at room temperature.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"147 3 1","pages":"67 - 79"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91117694","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. Secundino-Sánchez, J. Díaz-Reyes, J. F. Sánchez-Ramírez, J. S. Arias-Cerón, M. Galván-Arellano, Á. Guillén-Cervantes
TiO2 nanofibers were synthesised by means of the electrospun technique, which were annealed at high temperatures to achieve the crystalline phase transformation from amorphous to rutile through anatase and the phase mixture. The chemical stoichiometry of electrospun TiO2 nanofibers was estimated by EDS, finding that at low annealing temperatures excess of oxygen was detected and at high temperatures excess of titanium that originates oxygen vacancies. The TEM images showed clearly the formation of TiO2 nanofibers (NF’s) that exhibit a homogeneous and continuous aspect without the presence of crystalline defects, whose surface morphology depends strongly on the annealing temperature. The crystalline phase transformation was studied by Raman spectroscopy, which revealed that annealed TiO2 NF’s showed a crystalline phase transformation from amorphous, pure anatase, anatase-rutile mixed, to pure rutile as the annealing temperature increased, which was corroborated by X-ray diffraction and high-resolution TEM. The average grain size, inside the NF´s, increased with the crystalline phase transformation from 10 to 24 nm for anatase-TiO2 and from 30 to 47 nm for rutile-TiO2, which were estimated by using the Scherrer-Debye equation. By absorbance measurements at room temperature the band gap energy (Eg) was obtained, which is ranged in 3.75-2.42 eV, caused by the amorphous → anatase → anatase-rutile mixed → rutile crystalline phase transformation.
{"title":"Systematic Characterization of the Crystalline Phase Transformation, from Amorphous to Rutile through Anatase, of TiO2 Nanofibers Synthesised by Electrospun Technique","authors":"O. Secundino-Sánchez, J. Díaz-Reyes, J. F. Sánchez-Ramírez, J. S. Arias-Cerón, M. Galván-Arellano, Á. Guillén-Cervantes","doi":"10.4028/p-044t3c","DOIUrl":"https://doi.org/10.4028/p-044t3c","url":null,"abstract":"TiO2 nanofibers were synthesised by means of the electrospun technique, which were annealed at high temperatures to achieve the crystalline phase transformation from amorphous to rutile through anatase and the phase mixture. The chemical stoichiometry of electrospun TiO2 nanofibers was estimated by EDS, finding that at low annealing temperatures excess of oxygen was detected and at high temperatures excess of titanium that originates oxygen vacancies. The TEM images showed clearly the formation of TiO2 nanofibers (NF’s) that exhibit a homogeneous and continuous aspect without the presence of crystalline defects, whose surface morphology depends strongly on the annealing temperature. The crystalline phase transformation was studied by Raman spectroscopy, which revealed that annealed TiO2 NF’s showed a crystalline phase transformation from amorphous, pure anatase, anatase-rutile mixed, to pure rutile as the annealing temperature increased, which was corroborated by X-ray diffraction and high-resolution TEM. The average grain size, inside the NF´s, increased with the crystalline phase transformation from 10 to 24 nm for anatase-TiO2 and from 30 to 47 nm for rutile-TiO2, which were estimated by using the Scherrer-Debye equation. By absorbance measurements at room temperature the band gap energy (Eg) was obtained, which is ranged in 3.75-2.42 eV, caused by the amorphous → anatase → anatase-rutile mixed → rutile crystalline phase transformation.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"84 1","pages":"11 - 23"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83843400","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}
Zinc plays an important role as a micronutrient in both animals and plants. The application of zinc oxide nanoparticles as a potential solution to alleviate zinc deficiency and its effect on the growth of seedling attributes of wheat. These particles were prepared by precipitation and sol-gel method using zinc sulfate and zinc chloride as precursors. The prepared samples were characterized by Scanning electron microscopy and Fourier-transform spectroscopy. Zinc oxide nanoparticles were found to be elliptical in shape and their diameter ranges were observed 10.6 to 10.7nm by Scanning electron microscopy. Fourier-transform spectroscopy analyses showed the presence of the various functional group in the zinc oxide nanoparticles like N-H, CH2, CH3, RCH=CHR, C=O, -COOH, -OH and CH2-Cl. Solutions of different concentrations of zinc oxide nanoparticles (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) were prepared and seeds were soaked in distilled water (hydro priming). After the 6 days observations, it was found that nanoparticles (0.3%) prepared from the zinc sulfate by sol-gel method showed significant variation for germination and seedling attributes of wheat as compared to control. The decreasing order for the zinc chemicals was zinc sulfate nanoparticles > zinc chloride for methods sol-gel method > precipitation method > standard (original salt) and for the levels was 0.3% > 0.2% > 0.4% > 0.5% > 0.1% > hydro priming > control. In crux, nanoparticles prepared from zinc sulfate enhanced the germination of wheat as compared to control.
{"title":"Synthesis of Zinc Oxide Nanoparticles by Precipitation and Sol Gel Methods from Different Precursors and their Comparison Impact on Seedling Attributes of Wheat","authors":"F. Mehmood, H. Kousar, Faiza Hassan, Q. Zaman","doi":"10.4028/p-2sa57f","DOIUrl":"https://doi.org/10.4028/p-2sa57f","url":null,"abstract":"Zinc plays an important role as a micronutrient in both animals and plants. The application of zinc oxide nanoparticles as a potential solution to alleviate zinc deficiency and its effect on the growth of seedling attributes of wheat. These particles were prepared by precipitation and sol-gel method using zinc sulfate and zinc chloride as precursors. The prepared samples were characterized by Scanning electron microscopy and Fourier-transform spectroscopy. Zinc oxide nanoparticles were found to be elliptical in shape and their diameter ranges were observed 10.6 to 10.7nm by Scanning electron microscopy. Fourier-transform spectroscopy analyses showed the presence of the various functional group in the zinc oxide nanoparticles like N-H, CH2, CH3, RCH=CHR, C=O, -COOH, -OH and CH2-Cl. Solutions of different concentrations of zinc oxide nanoparticles (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) were prepared and seeds were soaked in distilled water (hydro priming). After the 6 days observations, it was found that nanoparticles (0.3%) prepared from the zinc sulfate by sol-gel method showed significant variation for germination and seedling attributes of wheat as compared to control. The decreasing order for the zinc chemicals was zinc sulfate nanoparticles > zinc chloride for methods sol-gel method > precipitation method > standard (original salt) and for the levels was 0.3% > 0.2% > 0.4% > 0.5% > 0.1% > hydro priming > control. In crux, nanoparticles prepared from zinc sulfate enhanced the germination of wheat as compared to control.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"88 1","pages":"25 - 35"},"PeriodicalIF":1.7,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85648408","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}
Pub Date : 2022-01-25DOI: 10.4028/www.scientific.net/JNanoR.71.13
S. Lin, L. Shan, Chengguo Ma, Mingming Yuan, Zirou Fang, Yanwei Xiao, Limin Dong, Dan Li, Yingkuo Guo
Heterojunction semiconductor photocatalysis is an auspicious technique for clear up organic pollutants from water, and have been of valuable strategy in the area of photocatalysis. Herein, electrophoretic deposition procedure was used to prepare α-Bi2O3/CdS type-Ⅱ heterojunction photocatalysts. The results of PL, Raman, and EIS show that there is a heterojunction effect in α-Bi2O3/CdS, which is propitious to improve the separation efficiency of photogenerated electron-hole pairs. The DFT calculation reveals that the work function of CdS (4.57 eV) is higher than that of α-Bi2O3 (3.37 eV), which facilitates the migrating of e- from the CB of α-Bi2O3 to the CB of CdS, and the migrating of h+ from the VB of CdS to the VB of α-Bi2O3, thus the e--h+ pairs with high redox ability are retained. The performances were assessed by degrading methyl orange (MO), acid magenta under simulated visible light irradiation. Under simulated visible light irradiation, BC45 composite exhibited the highest degradation efficiency of 87% (MO) and 81% (acid fuchsin) for 4 h, which was about 2 times higher than that of CdS (MO) and (acid fuchsin). It is believed that the dual characteristics of H2O wettability and dye adsorption performance in α-Bi2O3/CdS composites promote photocatalytic process compared with single CdS and α-Bi2O3. The study could provide new insights to develop efficiently capable photocatalysts of the α-Bi2O3/CdS composites.
{"title":"High-Performance α-Bi2O3/CdS Heterojunction Photocatalyst: Innovative Design, Electrochemical Performance and DFT Calculation","authors":"S. Lin, L. Shan, Chengguo Ma, Mingming Yuan, Zirou Fang, Yanwei Xiao, Limin Dong, Dan Li, Yingkuo Guo","doi":"10.4028/www.scientific.net/JNanoR.71.13","DOIUrl":"https://doi.org/10.4028/www.scientific.net/JNanoR.71.13","url":null,"abstract":"Heterojunction semiconductor photocatalysis is an auspicious technique for clear up organic pollutants from water, and have been of valuable strategy in the area of photocatalysis. Herein, electrophoretic deposition procedure was used to prepare α-Bi2O3/CdS type-Ⅱ heterojunction photocatalysts. The results of PL, Raman, and EIS show that there is a heterojunction effect in α-Bi2O3/CdS, which is propitious to improve the separation efficiency of photogenerated electron-hole pairs. The DFT calculation reveals that the work function of CdS (4.57 eV) is higher than that of α-Bi2O3 (3.37 eV), which facilitates the migrating of e- from the CB of α-Bi2O3 to the CB of CdS, and the migrating of h+ from the VB of CdS to the VB of α-Bi2O3, thus the e--h+ pairs with high redox ability are retained. The performances were assessed by degrading methyl orange (MO), acid magenta under simulated visible light irradiation. Under simulated visible light irradiation, BC45 composite exhibited the highest degradation efficiency of 87% (MO) and 81% (acid fuchsin) for 4 h, which was about 2 times higher than that of CdS (MO) and (acid fuchsin). It is believed that the dual characteristics of H2O wettability and dye adsorption performance in α-Bi2O3/CdS composites promote photocatalytic process compared with single CdS and α-Bi2O3. The study could provide new insights to develop efficiently capable photocatalysts of the α-Bi2O3/CdS composites.","PeriodicalId":16525,"journal":{"name":"Journal of Nano Research","volume":"10 1","pages":"13 - 28"},"PeriodicalIF":1.7,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72930616","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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