Pub Date : 2022-03-24DOI: 10.25073/2588-1124/vnumap.4660
D. Hai, V. Hùng, P. N. Thư, Lò Ngọc Dũng, Lê Thị Thanh Hương, H. T. Anh, Le Thu Lam
Effect of dopant on structural and electrical properties of samarium-doped ceria (SDC) electrolyte was investigated using statistical moment method. Our results showed the lattice expansion due to doping and local distortion resulting from preferential distribution of oxygen vacancies around dopants. The ionic conductivity of SDC crystals is in more than three orders of magnitude larger than that of pure ceria. However, the presence of dopant in cation edge and the first nearest neighbor positions around migrating vacancy gives rise to the blocking and trapping effects on the vacancy transport. The maximum value of the ionic conductivity was found for the samples with the dopant concentration x = 0.15. These results can be compared to the one of the published data of boththe theoretical and experimental investigations.
{"title":"Structural and Electrical Properties of Samarium-doped Ceria Electrolyte","authors":"D. Hai, V. Hùng, P. N. Thư, Lò Ngọc Dũng, Lê Thị Thanh Hương, H. T. Anh, Le Thu Lam","doi":"10.25073/2588-1124/vnumap.4660","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4660","url":null,"abstract":"Effect of dopant on structural and electrical properties of samarium-doped ceria (SDC) electrolyte was investigated using statistical moment method. Our results showed the lattice expansion due to doping and local distortion resulting from preferential distribution of oxygen vacancies around dopants. The ionic conductivity of SDC crystals is in more than three orders of magnitude larger than that of pure ceria. However, the presence of dopant in cation edge and the first nearest neighbor positions around migrating vacancy gives rise to the blocking and trapping effects on the vacancy transport. The maximum value of the ionic conductivity was found for the samples with the dopant concentration x = 0.15. These results can be compared to the one of the published data of boththe theoretical and experimental investigations.","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121566584","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 : 2022-03-24DOI: 10.25073/2588-1124/vnumap.4647
Nguyen Huu Nha, Phan Van Nham
The signature of the magnetic competition in a nearly filled impurity band diluted magnetic semiconductors is addressed. In the formalism of the Kondo lattice model, self-consistent equations determining the Green function of the itinerant carrier in the system are evaluated by use of the dynamical mean-field theory. An analytical solution of the static spin susceptibility of the itinerant carrier to specify the magnetic instability is then established. Once the impurity band is nearly filled, one finds the antiferromagnetic instability against the ferromagnetic state. Phase diagrams of the magnetic structures in the diluted magnetic semiconductor were also discussed.
{"title":"Ferromagnetic-antiferromagnetic Competition in Diluted Magnetic Semiconductors","authors":"Nguyen Huu Nha, Phan Van Nham","doi":"10.25073/2588-1124/vnumap.4647","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4647","url":null,"abstract":"The signature of the magnetic competition in a nearly filled impurity band diluted magnetic semiconductors is addressed. In the formalism of the Kondo lattice model, self-consistent equations determining the Green function of the itinerant carrier in the system are evaluated by use of the dynamical mean-field theory. An analytical solution of the static spin susceptibility of the itinerant carrier to specify the magnetic instability is then established. Once the impurity band is nearly filled, one finds the antiferromagnetic instability against the ferromagnetic state. Phase diagrams of the magnetic structures in the diluted magnetic semiconductor were also discussed. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127838656","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 : 2022-03-24DOI: 10.25073/2588-1124/vnumap.4671
Vu Dinh Khoe, Pham Minh Phuong, Nguyen Van Thanh, Tran Quoc Quan, Nguyen Dinh Duc
In this work we investigated the nonlinear vibration of nanocomposite multilayer perovskite solar cell (NMPSC) subjected to the combination of mechanical and thermal loadings. The model of organic solar cell is assumed to consist seven functional layers: Au, Spiro-OMeTAD, PEDOT:PSS, Graphene oxide, MAPbI3, TiO2 and IOT, and glass substrate. The governing equations are established basing on the classical plate theory taking into account the effect of elastic foundations and initial imperfection. Four edges of the NMPSC are assumed to be supported immovably in a transverse plane. The relationship between deflection amplitude and time as well as the expression of natural frequency of NMPSC are obtained by using the Galerkin and Runge – Kutta methods. The numerical results showed that the nonlinear dynamic response and the natural frequency of NMPSC have been strongly influenced by the geometrical and material parameters, initial imperfection, temperature increment and elastic foundations. Keywords: Perovskite solar cell; nonlinear vibration; elastic foundations; initial imperfection; thermal environment
{"title":"Nonlinear Vibration of Nanocomposite Multilayer Perovskite Solar Cell in Thermal Environment","authors":"Vu Dinh Khoe, Pham Minh Phuong, Nguyen Van Thanh, Tran Quoc Quan, Nguyen Dinh Duc","doi":"10.25073/2588-1124/vnumap.4671","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4671","url":null,"abstract":"In this work we investigated the nonlinear vibration of nanocomposite multilayer perovskite solar cell (NMPSC) subjected to the combination of mechanical and thermal loadings. The model of organic solar cell is assumed to consist seven functional layers: Au, Spiro-OMeTAD, PEDOT:PSS, Graphene oxide, MAPbI3, TiO2 and IOT, and glass substrate. The governing equations are established basing on the classical plate theory taking into account the effect of elastic foundations and initial imperfection. Four edges of the NMPSC are assumed to be supported immovably in a transverse plane. The relationship between deflection amplitude and time as well as the expression of natural frequency of NMPSC are obtained by using the Galerkin and Runge – Kutta methods. The numerical results showed that the nonlinear dynamic response and the natural frequency of NMPSC have been strongly influenced by the geometrical and material parameters, initial imperfection, temperature increment and elastic foundations. \u0000Keywords: Perovskite solar cell; nonlinear vibration; elastic foundations; initial imperfection; thermal environment","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114242534","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 : 2022-03-24DOI: 10.25073/2588-1124/vnumap.4685
Nguyen Van Thanh
This work deals with the nonlinear buckling and post-buckling of stiffened nanocomposite plates reinforced functionally graded carbon nanotubes (FG CNTRC) resting on elastic foundation in thermal environment. Obtained results showed that the properties of the nanocomposited plates embedded with single-walled carbon nanotubes are dependent on temperature and altered according to linear functions of the thickness. The governing equations are derived by the third-order shear deformation plate theory taking into account von Kármàn geometrical nonlinearity and solved by both the Airy’s stress function and Galerkin method. In numerical results, the influences of various types of distribution and volume fractions of carbon nanotubes, geometrical parameters, elastic foundations on the nonlinear buckling and post-buckling behaviour of stiffened FG-CNTC plates subjected mechanical, thermal loading and both are demonstrated. Keywords: Stiffened FG CNTRC plates; Buckling and Post buckling analysis; Third-order shear deformation theory; Thermal environment; Galerkin method This work deals with the nonlinear buckling and post-buckling of stiffened nanocomposite plates reinforced functionally graded carbon nanotubes (FG CNTRC) resting on elastic foundation in thermal environment. Obtained results showed that the properties of the nanocomposited plates embedded with single-walled carbon nanotubes are dependent on temperature and altered according to linear functions of the thickness. The governing equations are derived by the third-order shear deformation plate theory taking into account von Kármàn geometrical nonlinearity and solved by both the Airy’s stress function and Galerkin method. In numerical results, the influences of various types of distribution and volume fractions of carbon nanotubes, geometrical parameters, elastic foundations on the nonlinear buckling and post-buckling behaviour of stiffened FG-CNTC plates subjected mechanical, thermal loading and both are demonstrated.
{"title":"Nonlinear Static Stability of Stiffened Nanocomposite Plate s Subjected Various Types of Loads","authors":"Nguyen Van Thanh","doi":"10.25073/2588-1124/vnumap.4685","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4685","url":null,"abstract":"This work deals with the nonlinear buckling and post-buckling of stiffened nanocomposite plates reinforced functionally graded carbon nanotubes (FG CNTRC) resting on elastic foundation in thermal environment. Obtained results showed that the properties of the nanocomposited plates embedded with single-walled carbon nanotubes are dependent on temperature and altered according to linear functions of the thickness. The governing equations are derived by the third-order shear deformation plate theory taking into account von Kármàn geometrical nonlinearity and solved by both the Airy’s stress function and Galerkin method. In numerical results, the influences of various types of distribution and volume fractions of carbon nanotubes, geometrical parameters, elastic foundations on the nonlinear buckling and post-buckling behaviour of stiffened FG-CNTC plates subjected mechanical, thermal loading and both are demonstrated. \u0000Keywords: Stiffened FG CNTRC plates; Buckling and Post buckling analysis; Third-order shear deformation theory; Thermal environment; Galerkin method \u0000This work deals with the nonlinear buckling and post-buckling of stiffened nanocomposite plates reinforced functionally graded carbon nanotubes (FG CNTRC) resting on elastic foundation in thermal environment. Obtained results showed that the properties of the nanocomposited plates embedded with single-walled carbon nanotubes are dependent on temperature and altered according to linear functions of the thickness. The governing equations are derived by the third-order shear deformation plate theory taking into account von Kármàn geometrical nonlinearity and solved by both the Airy’s stress function and Galerkin method. In numerical results, the influences of various types of distribution and volume fractions of carbon nanotubes, geometrical parameters, elastic foundations on the nonlinear buckling and post-buckling behaviour of stiffened FG-CNTC plates subjected mechanical, thermal loading and both are demonstrated. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"126 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129798393","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 : 2021-12-08DOI: 10.25073/2588-1124/vnumap.4631
Tran Quang Huy, Pham Thi Thu Ha, Tran Binh Duong, Nguyen Quang Vinh, Nguyễn Thị Hoàng Yến, Tran Duc Tan
Shear wave imaging (SWI) is a rapid and convenient method of collecting images of tissues in the region of interest. SWI is based on the mechanical properties of soft tissues named the complex shear modulus (CSM). The complex shear modulus consisting of the elasticity and the viscosity, is useful for diagnosing pathological tissue conditions. Previous studies have not fully exploited the estimation of CSM in the medium containing Gaussian noise and the shear wave's reflection phenomenon. In this study, we focused on the model of shear wave propagation in the 2D environment by the time domain finite difference method (FDTD), taking into account the effect of Gaussian noise and reflected shear wave. We then reduced the noise of the measured particle velocity using a designed least mean square filter. Finally, for direct estimation of CSM, Helmholtz algebraic inverse transformation algorithm was used. Reflected waves significantly affect the estimation of CSM, especially the tissue's viscosity, which is demonstrated by numerical simulation results.
{"title":"2D Shear Wave Imaging in Gaussian Noise and Reflection Media","authors":"Tran Quang Huy, Pham Thi Thu Ha, Tran Binh Duong, Nguyen Quang Vinh, Nguyễn Thị Hoàng Yến, Tran Duc Tan","doi":"10.25073/2588-1124/vnumap.4631","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4631","url":null,"abstract":"Shear wave imaging (SWI) is a rapid and convenient method of collecting images of tissues in the region of interest. SWI is based on the mechanical properties of soft tissues named the complex shear modulus (CSM). The complex shear modulus consisting of the elasticity and the viscosity, is useful for diagnosing pathological tissue conditions. Previous studies have not fully exploited the estimation of CSM in the medium containing Gaussian noise and the shear wave's reflection phenomenon. In this study, we focused on the model of shear wave propagation in the 2D environment by the time domain finite difference method (FDTD), taking into account the effect of Gaussian noise and reflected shear wave. We then reduced the noise of the measured particle velocity using a designed least mean square filter. Finally, for direct estimation of CSM, Helmholtz algebraic inverse transformation algorithm was used. Reflected waves significantly affect the estimation of CSM, especially the tissue's viscosity, which is demonstrated by numerical simulation results. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122692197","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 : 2021-12-03DOI: 10.25073/2588-1124/vnumap.4625
Mai Thi Lan, N. T. Nhan, Nguyen Thi Thao, Pham Thi Dung
This work presents the effect of pressure on the local microstructure of amorphous Germania (GeO2). The Molecular Dynamics simulation was performed on systems at 900 K and high pressure up to 70 GPa. The structural properties have been analyzed through the pair correlation function, coordination number distribution, and structure factors. The structural phase transition process starts occurring at 30 GPa. At above 30 GPa, the degree of structural order increases and the intermediate-range order structure depends strongly on pressure. Correlation between the peaks in the plot of structure factor and the topology of basic structural units GeOn(n = 4-6) is also discussed in detail in this paper.
{"title":"A Simulation Study of the Amorphous Germania Structure up to 70 GPa","authors":"Mai Thi Lan, N. T. Nhan, Nguyen Thi Thao, Pham Thi Dung","doi":"10.25073/2588-1124/vnumap.4625","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4625","url":null,"abstract":"This work presents the effect of pressure on the local microstructure of amorphous Germania (GeO2). The Molecular Dynamics simulation was performed on systems at 900 K and high pressure up to 70 GPa. The structural properties have been analyzed through the pair correlation function, coordination number distribution, and structure factors. The structural phase transition process starts occurring at 30 GPa. At above 30 GPa, the degree of structural order increases and the intermediate-range order structure depends strongly on pressure. Correlation between the peaks in the plot of structure factor and the topology of basic structural units GeOn(n = 4-6) is also discussed in detail in this paper. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127927659","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 : 2021-12-03DOI: 10.25073/2588-1124/vnumap.4622
N. Toan, P. Nhat, Ta Van Duong
Microsphere biolasers have attracted a great deal of interest due to their potential in biosensing and cell-tracking. Various fabrication techniques have been explored for making microsphere biolasers, such as freeze-drying in a vacuum, standard oil in water dispersion procedure and protein dehydration in a solvent. The protein dehydration is highly interesting due to its simplicity and fast processing time. In this work, we demonstrate the fabrication of microsphere biolasers using protein dehydration in decanol and demonstrate that the fabrication process can speed up if the solvent is heated. When the solvent is heated to 60 °C, the fabrication time is reduced to half compared with the case when the sample is made at room temperature. Interestingly, while heating the solvent helps to decrease the fabrication time, it does not affect the lasing properties of the samples. The lasing thresholds of microsphere biolasers fabricated at 25 °C and 60 °C are similar. Furthermore, lasing operation under continuous pumping and lasing stability against storing time are also investigated. A typical 42 µm microsphere can still lase upon 2×104 excitation pulses. Lasers can work well after being stored for 12 weeks under ambient conditions.
{"title":"Fabricating Microsphere Lasers by Protein Dehydration: A Fast Fabrication Method and Excellent Lasing Properties","authors":"N. Toan, P. Nhat, Ta Van Duong","doi":"10.25073/2588-1124/vnumap.4622","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4622","url":null,"abstract":"Microsphere biolasers have attracted a great deal of interest due to their potential in biosensing and cell-tracking. Various fabrication techniques have been explored for making microsphere biolasers, such as freeze-drying in a vacuum, standard oil in water dispersion procedure and protein dehydration in a solvent. The protein dehydration is highly interesting due to its simplicity and fast processing time. In this work, we demonstrate the fabrication of microsphere biolasers using protein dehydration in decanol and demonstrate that the fabrication process can speed up if the solvent is heated. When the solvent is heated to 60 °C, the fabrication time is reduced to half compared with the case when the sample is made at room temperature. Interestingly, while heating the solvent helps to decrease the fabrication time, it does not affect the lasing properties of the samples. The lasing thresholds of microsphere biolasers fabricated at 25 °C and 60 °C are similar. Furthermore, lasing operation under continuous pumping and lasing stability against storing time are also investigated. A typical 42 µm microsphere can still lase upon 2×104 excitation pulses. Lasers can work well after being stored for 12 weeks under ambient conditions. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117131643","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 : 2021-12-03DOI: 10.25073/2588-1124/vnumap.4646
Le Huu Trinh, Nguyen Duc Cuong, Do Dang Trung, Nguyen Van Hieu
: In this study, hierarchical CeO2 spherical nanoparticles were fabricated by the polyol method using Ceri (III) acetate hydroxide, sodium hydroxide, and triethylene glycol as precursors. The product was characterized by XRD, SEM, and TEM. The results show that the cerium oxide spherical nanoparticles built from primary nanoparticles with the average size of ~5 nm, exhibited dispersion and uniform size and shapes with their average particle diameter of ~50 nm in size. With such a good morphology, CeO2 material possessed good catalytic activity for the decomposition of methylene blue (MB), in which the material was synthesized at a hydrothermal temperature of 80 oC (CeO2-80) for the best MB decomposition performance.
{"title":"Synthesis and Characterization of Hierarchical CeO2 Spherical Nanoparticles for Photocatalytic Degradation of Methylene Blue","authors":"Le Huu Trinh, Nguyen Duc Cuong, Do Dang Trung, Nguyen Van Hieu","doi":"10.25073/2588-1124/vnumap.4646","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4646","url":null,"abstract":": In this study, hierarchical CeO2 spherical nanoparticles were fabricated by the polyol method using Ceri (III) acetate hydroxide, sodium hydroxide, and triethylene glycol as precursors. The product was characterized by XRD, SEM, and TEM. The results show that the cerium oxide spherical nanoparticles built from primary nanoparticles with the average size of ~5 nm, exhibited dispersion and uniform size and shapes with their average particle diameter of ~50 nm in size. With such a good morphology, CeO2 material possessed good catalytic activity for the decomposition of methylene blue (MB), in which the material was synthesized at a hydrothermal temperature of 80 oC (CeO2-80) for the best MB decomposition performance. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125941894","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 : 2021-12-03DOI: 10.25073/2588-1124/vnumap.4607
Nguyen Dinh Lam
Zinc oxide is known as an excellent material for biosensors, solar cells, semiconductors and photocatalysts. In this work, n-ZnO nanorods/p-Si heterostructures were successfully fabricated by a hydrothermal method at different baking temperatures. The n-ZnO nanorods/p-Si heterostructures show good photocatalytic ability at high baking temperature. The concentration of Rhodamine B can be decreased up to 97% after 150 min treated by the n-ZnO nanorods/p-Si heterostructures grown at 80 oC. This result indicates that the n-ZnO nanorods/p-Si heterostructures are capable of being used in the decomposition of organic compounds.
{"title":"Influences of ZnO Nanorod Arrays on Photocatalytic Activity of n-ZnO Nanorods/p-Si Heterostructure","authors":"Nguyen Dinh Lam","doi":"10.25073/2588-1124/vnumap.4607","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4607","url":null,"abstract":"Zinc oxide is known as an excellent material for biosensors, solar cells, semiconductors and photocatalysts. In this work, n-ZnO nanorods/p-Si heterostructures were successfully fabricated by a hydrothermal method at different baking temperatures. The n-ZnO nanorods/p-Si heterostructures show good photocatalytic ability at high baking temperature. The concentration of Rhodamine B can be decreased up to 97% after 150 min treated by the n-ZnO nanorods/p-Si heterostructures grown at 80 oC. This result indicates that the n-ZnO nanorods/p-Si heterostructures are capable of being used in the decomposition of organic compounds. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125238877","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 : 2021-12-03DOI: 10.25073/2588-1124/vnumap.4649
Le Thi Ngoc Loan, Le Thi Thanh Hiep, Hoang Thi Hang, Le Xuan Hung
In this report, SERS substrates based on Ag-decorated TiO2 nanofibers electrospun on a glass substrate (Ag/TiO2/glass) were successfully prepared using electrospinning and photodeposition methods. XRD pattern demonstrated that the crystalline structure of TiO2 nanofibers (TiO2 NFs) consisted of both anatase and rutile phase. SEM images show that the randomly oriented on glass substrate TiO2 NFs’ diameters are in the range of 150 nm-300 nm and their lengths are up to a few micrometers. After 15-minute photodeposition, Ag NPs with average diameter of about a few tens of nanometers were uniformly and densely decorated on TiO2 NFs surface. The Ag/TiO2/glass SERS substrate was then immersed in 0.01 mM, 0.1 mM, and 1 mM 4-mercaptobenzoic acid (4-MBA) solution, and was afterwards investigated by UV-Vis absorption and Surface-enhanced Raman Scattering (SERS) spectra. The preliminary results show that the change in UV-Vis absorption corresponds well to the Raman peak intensity upon the adsorption of probed molecules. This might open up a pathway in the detection and identification of probed molecules based on colorimetric-sensing and SERS-sensing.
{"title":"Ag-decorated TiO2 Nanofibers for Surface-enhanced Raman Scattering","authors":"Le Thi Ngoc Loan, Le Thi Thanh Hiep, Hoang Thi Hang, Le Xuan Hung","doi":"10.25073/2588-1124/vnumap.4649","DOIUrl":"https://doi.org/10.25073/2588-1124/vnumap.4649","url":null,"abstract":"In this report, SERS substrates based on Ag-decorated TiO2 nanofibers electrospun on a glass substrate (Ag/TiO2/glass) were successfully prepared using electrospinning and photodeposition methods. XRD pattern demonstrated that the crystalline structure of TiO2 nanofibers (TiO2 NFs) consisted of both anatase and rutile phase. SEM images show that the randomly oriented on glass substrate TiO2 NFs’ diameters are in the range of 150 nm-300 nm and their lengths are up to a few micrometers. After 15-minute photodeposition, Ag NPs with average diameter of about a few tens of nanometers were uniformly and densely decorated on TiO2 NFs surface. The Ag/TiO2/glass SERS substrate was then immersed in 0.01 mM, 0.1 mM, and 1 mM 4-mercaptobenzoic acid (4-MBA) solution, and was afterwards investigated by UV-Vis absorption and Surface-enhanced Raman Scattering (SERS) spectra. The preliminary results show that the change in UV-Vis absorption corresponds well to the Raman peak intensity upon the adsorption of probed molecules. This might open up a pathway in the detection and identification of probed molecules based on colorimetric-sensing and SERS-sensing. \u0000 ","PeriodicalId":303178,"journal":{"name":"VNU Journal of Science: Mathematics - Physics","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115063254","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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