Pub Date : 2020-07-01DOI: 10.22052/JNS.2020.03.012
Hajar Rajaei Litkohi, A. Bahari, R. Ojani
In this study, carbon nanotubes (CNTs) were deposited directly on impregnated Fe/carbon paper (CP) substrate (CNT/CP) utilizing chemical vapor deposition (CVD) process with the aim of using them as electrocatalytic electrode. The influence of wet impregnation conditions and CVD growth parameters on the characteristics of CNTs was investigated. Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), Transmission electron microscopy (TEM) and Raman spectroscopy were applied to characterize nucleation, growth and morphology of CNTs on CP. Measurement of Contact angle (CA) determined 125.9 and 145.0 ⁰C for CP and CNT/CP that displayed an increase in water repellence and degree hydrophobicity of CNT/CP to 15% than CP. Electrochemical impedance spectroscopy (EIS) analysis indicated the reduction of electrode charge transfer resistance from 5000 ohm value from CNT/CP to ohm value for CP that shows the increment in electrical conductivity of CNTCP. Half-cell test analysis represented that the improvement of performance and the increase of power density to ⁓8 % for Pt/CNT/CP compared to commercial catalyst Pt/C/CP (20 wt%) even with about 42% less Pt loading, can be attributed to strong adhesion of in-situ CNTs to the CP and lower agglomeration of CNTs along with outstanding electrical and thermal conductivity of CNTs. The obtained results indicated that the proposed nanostructure serves as a promising candidate for many technological applications specially carbon nanotube-supported catalyst.
{"title":"Electrochemical and Microstructural Investigation of in-situ Grown CNTs Network on Carbon Paper as Electrocatalytic Electrode for Fuel Cells","authors":"Hajar Rajaei Litkohi, A. Bahari, R. Ojani","doi":"10.22052/JNS.2020.03.012","DOIUrl":"https://doi.org/10.22052/JNS.2020.03.012","url":null,"abstract":"In this study, carbon nanotubes (CNTs) were deposited directly on impregnated Fe/carbon paper (CP) substrate (CNT/CP) utilizing chemical vapor deposition (CVD) process with the aim of using them as electrocatalytic electrode. The influence of wet impregnation conditions and CVD growth parameters on the characteristics of CNTs was investigated. Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), Transmission electron microscopy (TEM) and Raman spectroscopy were applied to characterize nucleation, growth and morphology of CNTs on CP. Measurement of Contact angle (CA) determined 125.9 and 145.0 ⁰C for CP and CNT/CP that displayed an increase in water repellence and degree hydrophobicity of CNT/CP to 15% than CP. Electrochemical impedance spectroscopy (EIS) analysis indicated the reduction of electrode charge transfer resistance from 5000 ohm value from CNT/CP to ohm value for CP that shows the increment in electrical conductivity of CNTCP. Half-cell test analysis represented that the improvement of performance and the increase of power density to ⁓8 % for Pt/CNT/CP compared to commercial catalyst Pt/C/CP (20 wt%) even with about 42% less Pt loading, can be attributed to strong adhesion of in-situ CNTs to the CP and lower agglomeration of CNTs along with outstanding electrical and thermal conductivity of CNTs. The obtained results indicated that the proposed nanostructure serves as a promising candidate for many technological applications specially carbon nanotube-supported catalyst.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"564-580"},"PeriodicalIF":1.4,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47058115","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}
Pub Date : 2020-07-01DOI: 10.22052/JNS.2020.03.019
M. Zeraati, K. Tahmasebi, A. Irannejad
SiC nanocrystals are synthesized by sol-gel processing with tetraethoxysilane and green carbon sources (sugar, molasses, and stevia extract) as starting materials. The reactions of carbon precursors and silicon were investigated using density functional theory. To obtain the discrepancy between the energy levels of the interacting orbitals of precursors, molecules were optimized using B3LYP/6-31+G(d,p) method. XRD, FE-SEM, TG-DTA and FTIR analysis were implemented in order to compare the efficiency of different carbon sources. According to XRD experiments, SiC nanocrystals prepared by sugar and molasses had no contamination, while the sample prepared by stevia has impurity in the form of carbon and silica. TG-DTA results revealed that this difference is due to the fact that the carbon source in stevia did not react efficiently with silicon. Moreover, based on the DFT study and HOMO and LUMO analysis on the reactive energy of silicon and carbon precursors, it is revealed that sugar has the best reactivity among carbon sources for SiC formation.
{"title":"Formation of SiC nanocrystals prepared by sol-gel processing of green carbon sources and DFT calculations","authors":"M. Zeraati, K. Tahmasebi, A. Irannejad","doi":"10.22052/JNS.2020.03.019","DOIUrl":"https://doi.org/10.22052/JNS.2020.03.019","url":null,"abstract":"SiC nanocrystals are synthesized by sol-gel processing with tetraethoxysilane and green carbon sources (sugar, molasses, and stevia extract) as starting materials. The reactions of carbon precursors and silicon were investigated using density functional theory. To obtain the discrepancy between the energy levels of the interacting orbitals of precursors, molecules were optimized using B3LYP/6-31+G(d,p) method. XRD, FE-SEM, TG-DTA and FTIR analysis were implemented in order to compare the efficiency of different carbon sources. According to XRD experiments, SiC nanocrystals prepared by sugar and molasses had no contamination, while the sample prepared by stevia has impurity in the form of carbon and silica. TG-DTA results revealed that this difference is due to the fact that the carbon source in stevia did not react efficiently with silicon. Moreover, based on the DFT study and HOMO and LUMO analysis on the reactive energy of silicon and carbon precursors, it is revealed that sugar has the best reactivity among carbon sources for SiC formation.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"660-670"},"PeriodicalIF":1.4,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48175804","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}
Pub Date : 2020-07-01DOI: 10.22052/JNS.2020.03.017
A. Hamisu, U. Gaya, A. Gaya
Titanium dioxide nanowires have been prepared by the alkali hydrothermal treatment of TiO2 nanoparticles in presence of different hydroxides and characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), N2 adsorption-desorption measurements, powder x-ray diffraction (XRD) and UV-Vis spectroscopy. Interestingly, only the strong bases (NaOH and KOH) formed mainly anatase titanium dioxide nanowires with the evident collapse of definitive (110) rutile XRD peak. The KOH-based titanium oxide nanowires exhibited comparatively low diameter (∼5 nm), high surface area (228.34 m2/g), and low band gap energy (2.90 eV), and showed the most remarkable photocatalytic degradation (98.87 %). However, the NH4OH-based titanium dioxides were nanoparticles having insignificantly modified morphology and least photocatalytic efficiency. The effect of operating variables on the degradation of aqueous methylene blue (MB) over the obtained alkali hydrothermal TiO2 was studied using response surface methodology, based on a bivariate central composite design (CCD) and optimized numerically.
{"title":"Effect of alkali strength on the hydrothermal growth of photoactive TiO2 nanowires","authors":"A. Hamisu, U. Gaya, A. Gaya","doi":"10.22052/JNS.2020.03.017","DOIUrl":"https://doi.org/10.22052/JNS.2020.03.017","url":null,"abstract":"Titanium dioxide nanowires have been prepared by the alkali hydrothermal treatment of TiO2 nanoparticles in presence of different hydroxides and characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive x-ray (EDX), N2 adsorption-desorption measurements, powder x-ray diffraction (XRD) and UV-Vis spectroscopy. Interestingly, only the strong bases (NaOH and KOH) formed mainly anatase titanium dioxide nanowires with the evident collapse of definitive (110) rutile XRD peak. The KOH-based titanium oxide nanowires exhibited comparatively low diameter (∼5 nm), high surface area (228.34 m2/g), and low band gap energy (2.90 eV), and showed the most remarkable photocatalytic degradation (98.87 %). However, the NH4OH-based titanium dioxides were nanoparticles having insignificantly modified morphology and least photocatalytic efficiency. The effect of operating variables on the degradation of aqueous methylene blue (MB) over the obtained alkali hydrothermal TiO2 was studied using response surface methodology, based on a bivariate central composite design (CCD) and optimized numerically.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"639-651"},"PeriodicalIF":1.4,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48512021","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}
Pub Date : 2020-07-01DOI: 10.22052/JNS.2020.03.014
A. D. Khalaji, M. Jarošová, P. Machek, Kunfeng Chen, D. Xue
In this research, a convenient, simple and rapid route for the preparation of Co3O4 nanoparticles using the calcination of Co(NO3)2∙6H2O at the presence of benzoic acid (1:1 weight ratio) is reported. Further, the as-prepared Co3O4 nanoparticles were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). XRD result confirmed the Co3O4 nanoparticles are pure phase and the average crystallite size for Co3O4 nanoparticles was found 77 nm. The TEM images reveal nanoparticles with size ranging from 50 to 100 nm, which is in conformity with the calculation of average crystallite sizes from XRD patterns. Furthermore, the prepared Co3O4 nanoparticles were investigated as an anode material for Li-ion batteries. Results showed that the Co3O4 nanoparticles exhibited excellent electrochemical performance and cycling stability, a capacity of 1127 mA h g-1 was obtained at 100 mAg-1 and the samples exhibited stable discharge behavior up to 130 cycles with high rate capability.
本研究报道了一种方便、简单、快速的制备纳米Co3O4的方法，即在苯甲酸存在下，以1:1的质量比煅烧Co(NO3)2∙6H2O制备纳米Co3O4。利用x射线粉末衍射(XRD)和透射电子显微镜(TEM)对制备的Co3O4纳米颗粒进行了表征。XRD结果证实了纳米Co3O4为纯相，纳米Co3O4平均晶粒尺寸为77 nm。TEM图像显示纳米颗粒尺寸在50 ~ 100 nm之间，这与XRD图计算的平均晶粒尺寸一致。并对制备的Co3O4纳米颗粒作为锂离子电池负极材料进行了研究。结果表明，Co3O4纳米颗粒具有优异的电化学性能和循环稳定性，在100 mAg-1下可获得1127 mA h -1的放电容量，并且具有高达130次的高倍率放电性能。
{"title":"Co3O4 Nanoparticles : Synthesis, Characterization and Its Application as Performing Anode in Li-Ion Batteries","authors":"A. D. Khalaji, M. Jarošová, P. Machek, Kunfeng Chen, D. Xue","doi":"10.22052/JNS.2020.03.014","DOIUrl":"https://doi.org/10.22052/JNS.2020.03.014","url":null,"abstract":"In this research, a convenient, simple and rapid route for the preparation of Co3O4 nanoparticles using the calcination of Co(NO3)2∙6H2O at the presence of benzoic acid (1:1 weight ratio) is reported. Further, the as-prepared Co3O4 nanoparticles were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). XRD result confirmed the Co3O4 nanoparticles are pure phase and the average crystallite size for Co3O4 nanoparticles was found 77 nm. The TEM images reveal nanoparticles with size ranging from 50 to 100 nm, which is in conformity with the calculation of average crystallite sizes from XRD patterns. Furthermore, the prepared Co3O4 nanoparticles were investigated as an anode material for Li-ion batteries. Results showed that the Co3O4 nanoparticles exhibited excellent electrochemical performance and cycling stability, a capacity of 1127 mA h g-1 was obtained at 100 mAg-1 and the samples exhibited stable discharge behavior up to 130 cycles with high rate capability.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"607-612"},"PeriodicalIF":1.4,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42347314","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}
Pub Date : 2020-07-01DOI: 10.22052/JNS.2020.03.013
Azam Zamani, A. Mahjoub, M. Sadjadi
We have fabricated novel MnFe2O4@ZnO–GO and MnFe2O4@ZnO–rGO nanocomposites through chemical facile hydrothermal procedure at low temperature of 180 °C for 3h.We reported the successfully synthesis of the MnFe2O4@ZnO nanocomposite via the co-precipitation method and was calcined at 200 °C for 3 h. Our synthesis of MnFe2O4@ZnO modified by the different weight percentages of GO and rGO.The as-synthesized samples were investigated by techniques XRD, FE-SEM, EDS, TEM,FT-IR,UV-DRS, PL, BET. TEM observations have displayed that MnFe2O4@ZnO nanoparticles were deposited on the graphene oxide and reduced graphene oxide surface. Magnetic studies demonstrated that the MnFe2O4@ZnO–GO and MnFe2O4@ZnO–rGO nanocomposites can be used as a magnetically separable photocatalyst.The photodegradation efficiency of the prepared materials was evaluated by the decomposition of Congo Red (CR) in 35 min of natural sunlight irradiation. Among the synthesized materials, the MnFe2O4@ZnO-GO photocatalyst showed maximum photocatalytic activity(99.54 % ).We also investigated the role of some scavengers in the degradation procedures to study the effect of active species. The studies from the radical scavengertests showed that active radicals like •O2 -, e, h+, and •OH were involved in the photodegradation of CR dye. The experimental results were applied to illustrate the proposed mechanism ability for improved photocatalysis. The Kinetics investigations have revealed that the degradation of CR by the prepared photocatalysts follows the pseudo-first-order kinetics and the rate constant attained for MnFe2O4@ZnO-GO (k = 78.10-3 min−1) was higher than of MnFe2O4@ZnO-rGO (k = 57.10−3 min−1).
{"title":"Synthesis and characterization of MnFe2O4@ZnO-GO and MnFe2O4@ZnO-rGO nanocomposites with evaluation of improved Photocatalytic performance Under Sun Light","authors":"Azam Zamani, A. Mahjoub, M. Sadjadi","doi":"10.22052/JNS.2020.03.013","DOIUrl":"https://doi.org/10.22052/JNS.2020.03.013","url":null,"abstract":"We have fabricated novel MnFe2O4@ZnO–GO and MnFe2O4@ZnO–rGO nanocomposites through chemical facile hydrothermal procedure at low temperature of 180 °C for 3h.We reported the successfully synthesis of the MnFe2O4@ZnO nanocomposite via the co-precipitation method and was calcined at 200 °C for 3 h. Our synthesis of MnFe2O4@ZnO modified by the different weight percentages of GO and rGO.The as-synthesized samples were investigated by techniques XRD, FE-SEM, EDS, TEM,FT-IR,UV-DRS, PL, BET. TEM observations have displayed that MnFe2O4@ZnO nanoparticles were deposited on the graphene oxide and reduced graphene oxide surface. Magnetic studies demonstrated that the MnFe2O4@ZnO–GO and MnFe2O4@ZnO–rGO nanocomposites can be used as a magnetically separable photocatalyst.The photodegradation efficiency of the prepared materials was evaluated by the decomposition of Congo Red (CR) in 35 min of natural sunlight irradiation. Among the synthesized materials, the MnFe2O4@ZnO-GO photocatalyst showed maximum photocatalytic activity(99.54 % ).We also investigated the role of some scavengers in the degradation procedures to study the effect of active species. The studies from the radical scavengertests showed that active radicals like •O2 -, e, h+, and •OH were involved in the photodegradation of CR dye. The experimental results were applied to illustrate the proposed mechanism ability for improved photocatalysis. The Kinetics investigations have revealed that the degradation of CR by the prepared photocatalysts follows the pseudo-first-order kinetics and the rate constant attained for MnFe2O4@ZnO-GO (k = 78.10-3 min−1) was higher than of MnFe2O4@ZnO-rGO (k = 57.10−3 min−1).","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"581-606"},"PeriodicalIF":1.4,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46527664","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}
Pub Date : 2020-04-01DOI: 10.22052/JNS.2020.02.009
Nurhafizah Disa, Shi Yuan Khor, K. L. Tan, Soga Tetsuo
In this work, activated carbon (AC) derived from biomass wastes was implemented as electrode materials in supercapacitor application. This study has adopted rubber seed shell (RSS) wastes to derive AC via pyrolysis process. Meanwhile, reduced graphene oxide (rGO) was used as an additive material in order to study the effect of the rGO in capacitive behavior. The synthesized rGO was successfully produced through the electrochemical exfoliation method then further chemically reduced the solution using hydrazine hydrate. Four different electrodes were fabricated using a spin coating method to investigate the effect of added rGO to the capacitive behavior. One sample of AC/polyvinyl alcohol (PVA) as reference was prepared with ratio 2:8. Meanwhile, the three samples were prepared with different volumes of rGO. A series of techniques to characterize the morphological and structural properties of the samples have been carried out using field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX), atomic force microscopy (AFM), and Brunauer-Emmett-Teller (BET) surface analysis. Based on the cyclic measurements, AC/PVA/rGO2 showed the lowest resistivity which was 3.74 and consequently enhanced at least 10 orders in capacitive performance as compared to bare AC/PVA. Therefore, the capability of small amount rGO in enhancing the capacitive behavior paves the way for versatile practical applications in the electronic field.
{"title":"The Synthesized Reduced Graphene Oxide Enhanced the Capacitive Behavior of Activated Carbon/PVA as Potential Electrode Materials","authors":"Nurhafizah Disa, Shi Yuan Khor, K. L. Tan, Soga Tetsuo","doi":"10.22052/JNS.2020.02.009","DOIUrl":"https://doi.org/10.22052/JNS.2020.02.009","url":null,"abstract":"In this work, activated carbon (AC) derived from biomass wastes was implemented as electrode materials in supercapacitor application. This study has adopted rubber seed shell (RSS) wastes to derive AC via pyrolysis process. Meanwhile, reduced graphene oxide (rGO) was used as an additive material in order to study the effect of the rGO in capacitive behavior. The synthesized rGO was successfully produced through the electrochemical exfoliation method then further chemically reduced the solution using hydrazine hydrate. Four different electrodes were fabricated using a spin coating method to investigate the effect of added rGO to the capacitive behavior. One sample of AC/polyvinyl alcohol (PVA) as reference was prepared with ratio 2:8. Meanwhile, the three samples were prepared with different volumes of rGO. A series of techniques to characterize the morphological and structural properties of the samples have been carried out using field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX), atomic force microscopy (AFM), and Brunauer-Emmett-Teller (BET) surface analysis. Based on the cyclic measurements, AC/PVA/rGO2 showed the lowest resistivity which was 3.74 and consequently enhanced at least 10 orders in capacitive performance as compared to bare AC/PVA. Therefore, the capability of small amount rGO in enhancing the capacitive behavior paves the way for versatile practical applications in the electronic field.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"296-306"},"PeriodicalIF":1.4,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45343935","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}
Pub Date : 2020-04-01DOI: 10.22052/JNS.2020.02.003
S. A. Khudair, H. Jappor
First-principle calculations have been investigated to study the adsorption of the molecules (SO2, CO, NH3, CO2, NO2, and NO) on the surface of mono boron (B) B-doped and dual B-doped graphene sheets to explore their potential applications as sensors. Our findings indicate that the adsorption of (CO and NH3) on B-doped graphene and (CO and SO2) on dual B-doped graphene are weak physisorption with adsorption energy between (0.128 to 0.810) eV. However, the adsorption of (CO2, NO2, SO2, and NO) on B-doped graphene and (CO2, NH3, NO and NO2) on dual B-doped graphene are strong chemisorption. The strong interaction of (CO2, NO2, SO2, and NO) on B-doped graphene and (CO2, NH3, NO and NO2) on dual B-doped graphene demonstrating that B-doped graphene and dual B-doped graphene could catalyse or activate, suggesting the possibility of B-doped graphene and dual B-doped graphene as a catalyst. Moreover, the energy gap of B-doped graphene and dual B-doped graphene is opened upon adsorption of (CO, CO2, NH3, NO, NO2 and SO2) in various ways. Our calculations demonstrate the feasibility of B-doped graphene may be a good sensor for (CO and NH3) and dual B-doped graphene could be a good sensor for (CO and SO2).
{"title":"Adsorption of Gas Molecules on Graphene Doped with Mono and Dual Boron as Highly Sensitive Sensors and Catalysts","authors":"S. A. Khudair, H. Jappor","doi":"10.22052/JNS.2020.02.003","DOIUrl":"https://doi.org/10.22052/JNS.2020.02.003","url":null,"abstract":"First-principle calculations have been investigated to study the adsorption of the molecules (SO2, CO, NH3, CO2, NO2, and NO) on the surface of mono boron (B) B-doped and dual B-doped graphene sheets to explore their potential applications as sensors. Our findings indicate that the adsorption of (CO and NH3) on B-doped graphene and (CO and SO2) on dual B-doped graphene are weak physisorption with adsorption energy between (0.128 to 0.810) eV. However, the adsorption of (CO2, NO2, SO2, and NO) on B-doped graphene and (CO2, NH3, NO and NO2) on dual B-doped graphene are strong chemisorption. The strong interaction of (CO2, NO2, SO2, and NO) on B-doped graphene and (CO2, NH3, NO and NO2) on dual B-doped graphene demonstrating that B-doped graphene and dual B-doped graphene could catalyse or activate, suggesting the possibility of B-doped graphene and dual B-doped graphene as a catalyst. Moreover, the energy gap of B-doped graphene and dual B-doped graphene is opened upon adsorption of (CO, CO2, NH3, NO, NO2 and SO2) in various ways. Our calculations demonstrate the feasibility of B-doped graphene may be a good sensor for (CO and NH3) and dual B-doped graphene could be a good sensor for (CO and SO2).","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"217-229"},"PeriodicalIF":1.4,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43658600","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}
Pub Date : 2020-04-01DOI: 10.22052/JNS.2020.02.014
Z. Amirsardari, Akram Dourani, F. Hasanpour, Mohamad Ali Amirifar, Nooredin Ghadiri Massoom
To discuss the potential role of the support for iridium catalyst, we have proceeded to prepare a series of supported catalysts with the same active phase content, but different silica content, to elucidate the changes in surface structure and the reaction process of hydrous hydrazine decomposition on catalyst. The obtained iridium catalysts contained 20 wt% of nanoparticles dispersed on spherical mesoporous alumina and aluminosilicate supports for hydrogen generation from hydrous hydrazine. Iridium nanoparticles with different morphologies and diameters could be produced over the catalyst supports depending on its nature. The iridium catalysts were characterized by some techniques such as XRD, FESEM, BET, TGA, H2-TPR, and mechanical properties. The type of catalyst support played an important role in the effectiveness of the catalyst particles, leading to different activities for hydrazine monohydrate decomposition. Under the given test conditions, the performance of the catalyst was better when using alumina granular as the catalyst support than when using aluminosilicate granular. Since the aluminosilicate support was less reactive than the alumina, hydrogen selectivity was relatively small; consequently, the reaction rate was lower when using the aluminosilicate support than when using the alumina support.
{"title":"Effect of Silica Content on Support-Iridium Active Phase Interactions on the Nanocatalyst Activity","authors":"Z. Amirsardari, Akram Dourani, F. Hasanpour, Mohamad Ali Amirifar, Nooredin Ghadiri Massoom","doi":"10.22052/JNS.2020.02.014","DOIUrl":"https://doi.org/10.22052/JNS.2020.02.014","url":null,"abstract":"To discuss the potential role of the support for iridium catalyst, we have proceeded to prepare a series of supported catalysts with the same active phase content, but different silica content, to elucidate the changes in surface structure and the reaction process of hydrous hydrazine decomposition on catalyst. The obtained iridium catalysts contained 20 wt% of nanoparticles dispersed on spherical mesoporous alumina and aluminosilicate supports for hydrogen generation from hydrous hydrazine. Iridium nanoparticles with different morphologies and diameters could be produced over the catalyst supports depending on its nature. The iridium catalysts were characterized by some techniques such as XRD, FESEM, BET, TGA, H2-TPR, and mechanical properties. The type of catalyst support played an important role in the effectiveness of the catalyst particles, leading to different activities for hydrazine monohydrate decomposition. Under the given test conditions, the performance of the catalyst was better when using alumina granular as the catalyst support than when using aluminosilicate granular. Since the aluminosilicate support was less reactive than the alumina, hydrogen selectivity was relatively small; consequently, the reaction rate was lower when using the aluminosilicate support than when using the alumina support.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"348-361"},"PeriodicalIF":1.4,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48085763","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}
Pub Date : 2020-04-01DOI: 10.22052/JNS.2020.02.001
M. Monsefi, T. Tajerian, A. Rowan
Gold nanostar particles were synthesized using seed-mediated method. Au-seed was synthesized with the diameter of approximately 3 nm and a considerably low STDEV of less than 1 nm. Then, different amount of Au seed was introduced into the growth solution of nanostars and the influence of the changes in concentration of Au seed on the growth process was investigated. The size of gold nanostars increased with decreasing the concentration of Au seeds. We further extended this method to enable size-control of gold nanostars from approximately 70 nm to 140 nm in size. Also the longer branch length caused red shifting of resonant plasmonic peaks in the absorption spectra of the sample with the lower amount of Au seed. Thanks to this method, we could control size, and spikes of gold nanostars and the obtained results broaden the concept of the formation and morphology of gold nanostars. The plasmon band shift was attributed to variations in branch numbers, and overall star size.
{"title":"Size-controlled synthesis of gold nanostars and their characterizations and plasmon resonances","authors":"M. Monsefi, T. Tajerian, A. Rowan","doi":"10.22052/JNS.2020.02.001","DOIUrl":"https://doi.org/10.22052/JNS.2020.02.001","url":null,"abstract":"Gold nanostar particles were synthesized using seed-mediated method. Au-seed was synthesized with the diameter of approximately 3 nm and a considerably low STDEV of less than 1 nm. Then, different amount of Au seed was introduced into the growth solution of nanostars and the influence of the changes in concentration of Au seed on the growth process was investigated. The size of gold nanostars increased with decreasing the concentration of Au seeds. We further extended this method to enable size-control of gold nanostars from approximately 70 nm to 140 nm in size. Also the longer branch length caused red shifting of resonant plasmonic peaks in the absorption spectra of the sample with the lower amount of Au seed. Thanks to this method, we could control size, and spikes of gold nanostars and the obtained results broaden the concept of the formation and morphology of gold nanostars. The plasmon band shift was attributed to variations in branch numbers, and overall star size.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"198-205"},"PeriodicalIF":1.4,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48620072","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}
Pub Date : 2020-04-01DOI: 10.22052/JNS.2020.02.012
S. Chin, Asniar Salim, S. Pang
Hydroxypropyl starch was synthesized by modified sago starch with hydroxypropylation reaction. Hydroxypropyl starch nanoparticles with mean particle sizes of 110 nm are obtained by controlled precipitation through the drop-wise addition of dissolved hydroxypropyl starch solution into excess absolute ethanol. Piperine was loaded onto hydroxypropyl starch nanoparticles and native starch nanoparticles via the in-situ nanoprecipitation process. Hydroxypropyl starch nanoparticles exhibited higher piperine loading capacity as compared to native starch nanoparticles with the maximum loading capacity of 0.46 and 0.33 mg.mg-1, respectively. Piperine was release from hydroxypropyl starch nanoparticles in a slow and sustained manner at pH 1.2 over the period of 24 hours. Whereas piperine was completely released from native starch nanoparticles within 16 hours.
{"title":"Hydroxypropyl Starch Nanoparticles as Controlled Release","authors":"S. Chin, Asniar Salim, S. Pang","doi":"10.22052/JNS.2020.02.012","DOIUrl":"https://doi.org/10.22052/JNS.2020.02.012","url":null,"abstract":"Hydroxypropyl starch was synthesized by modified sago starch with hydroxypropylation reaction. Hydroxypropyl starch nanoparticles with mean particle sizes of 110 nm are obtained by controlled precipitation through the drop-wise addition of dissolved hydroxypropyl starch solution into excess absolute ethanol. Piperine was loaded onto hydroxypropyl starch nanoparticles and native starch nanoparticles via the in-situ nanoprecipitation process. Hydroxypropyl starch nanoparticles exhibited higher piperine loading capacity as compared to native starch nanoparticles with the maximum loading capacity of 0.46 and 0.33 mg.mg-1, respectively. Piperine was release from hydroxypropyl starch nanoparticles in a slow and sustained manner at pH 1.2 over the period of 24 hours. Whereas piperine was completely released from native starch nanoparticles within 16 hours.","PeriodicalId":16523,"journal":{"name":"Journal of Nanostructures","volume":"10 1","pages":"327-336"},"PeriodicalIF":1.4,"publicationDate":"2020-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68411363","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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