Zahid M.Yasmin N.Mirza M.Ashiq M.N....
5页查看更多>>摘要：? 2021 Elsevier B.V.A novel supercapacitor based on cerium sulfide and graphene oxide nanocomposite was synthesized with high power density by hydrothermal method in the existence (presence) of Graphene oxide (GO). The Graphene based materials have been assumed to be auspicious candidate for renewable energy applications as due to its unique monolayer bonding configuration of graphene oxide it provides large surface area to metal oxide or metal sulfides that enhance the capacitance of composite of GO/metal sulfide. Characterization of the prepared GO/Ce2S3 composite samples was done by XRD, SEM, FTIR and Raman spectroscopy. Cyclic volumetric (CV), galvanostatic charge-discharge (GCD) and the electrochemical impedance were performed in 2 M KOH solution to investigate electrochemical measurements. Electrochemical characterization of composite revealed that by introducing the rare earth sulfide in GO, the power density of material increases more than 3 times at a current density of 0.3Ag?1using GCD graph. The specific capacitance of composite at scan rate of 10 mV/s is 53 F/g which is comparable to GO (59 F/g) but on the other hand the power density of composite is 9 times greater than power density of GO. The above mentioned characteristics make this fabricated composite to be more compatible candidate for electrochemical application with high power and energy density.
原文链接:
NSTL
Elsevier
Xiao W.-Z.Meng B.Hu A.-M.Zhang X.-H....
5页查看更多>>摘要：? 2021 Elsevier B.V.A new category of tubular nanostructures solely composed of selenium was explored by using the density functional theory. Similar to those in carbon nanotubes, the armchair and zigzag tube-like structures formed as a roll-up α-Se nanoribbon. The zigzag (n ≤ 16, 0) nanotubes exhibit decreasingly narrow direct band gap, and the armchair (n, n) possess decreasingly moderate indirect gap. The strain energy of nanotubes is inversely proportional to the second power of the nanotube diameter. With increasing tube diameter, an initial rise and consequent decrease occurred in the effective masses to the limit value of α-Se monolayer. The carrier mobility of nanotubes is comparable with that of its monolayer with orders of 103 and 102 cm2V?1s?1 for electron and hole, respectively. The optical absorption spectra of α-Se nanotubes exhibit high absorbance in energy window cover the entire visible light spectrum. Therefore, α-Se nanotubes hold great potential for future applications in high-performance optoelectronics.
原文链接:- NSTL
- Elsevier
R R.Xu Y.Maroof Z.Hu X....
5页查看更多>>摘要：? 2021We study the effects of strain and oxygen vacancy on the electronic structure of the (SrMmO3)2/(LaAlO3)2.5 heterostructure based on the first-principles calculations of density functional theory. The results show that different strains change the occupation of the eg orbitals of Mn, which makes the system have different magnetic ground states and electronic properties. It is also found that the conductivity of the (SrMmO3)2/(LaAlO3)2.5 system increases with the increase of oxygen vacancies rate, which can be used for the new generation electronic devices.
原文链接:- NSTL
- Elsevier
K K N.Manthrammel M.A.Shkir M.AlFaify S....
5页查看更多>>摘要：? 2021 Elsevier B.V.We report the possibility of room temperature d0Dilute Magnetic Semiconductor (d0DMS) behavior in organic capped Zinc Oxide (ZnO) nanoparticles. The uncapped and organic capped ZnO nanoparticles were prepared through a simple chemical synthesis technique. Tri-n-Octyl Phosphine Oxide (TOPO) and Dodecyle amine (DDA) were used as the capping agents. X-ray diffraction studies reveal that the organically capped nanoparticles were compressively strained. X-ray Photoelectron spectroscopy demonstrated that strain in the nanoparticles arise as the capping promotes vacancy sites for oxygen in ZnO nanocrystals. The magnetic measurements showed a room temperature ferromagnetic ordering in the as prepared ZnO nanoparticles samples. The observed ferromagnetism can be mainly attributed to positional defects in ZnO nanocrystals. In addition, the surface electronic configuration, which is modified by the capping molecules wrapped on the surface of ZnO nanoparticles, also has a key role in the origin of ferromagnetism.
原文链接:- NSTL
- Elsevier
Zou X.Ke J.Hao J.Yan X....
5页查看更多>>摘要：? 2021 Elsevier B.V.ZnO flower-like nanostructures have been successfully synthesized by a new and facile hydrothermal method. Their crystal structures and photocatalytic performance were also investigated. The amount of surfactant cetyltrimethyl ammonium bromide (CTAB) added to the precursor had an important effect on the ultimate morphology of the ZnO flower-like nanostructures. As the CTAB amount increased, the petals of the ZnO nanoflowers architecture changed from nanorods to nanosheets. In addition, for the nanoflowers assembled by nanosheets, the thickness of nanosheet can be controlled by adjusting the CTAB amount. The plausible growth mechanisms of the ZnO flower-like nanostructures were proposed. Furthermore, the nanosheets-assembled nanoflowers exhibited better photocatalytic performance than the nanorods-assembled nanoflowers toward Rhodamine B owning to their larger specific area and more OH groups absorbed on the nanosheet surface.
原文链接:- NSTL
- Elsevier
Charola S.Parmar J.Suresh Kumar R.Patel S.K....
5页查看更多>>摘要：? 2021 Elsevier B.V.In this paper, a broadband metasurface absorber using phase change material covering the visible region (500 THz to 740 THz) is numerically investigated. The top metallic layer comprises an array of Jerusalem shaped structures periodic in the x-y direction placed above the Ge2Sb2Te5 (GST) layer. The GST layer is followed by a thick metallic layer and silicon dioxide (SiO2). The intermediate dielectric layer in between two metallic layers is made of phase change material. The tri-layer structure is placed above the SiO2 with average absorption is achieved with an efficiency of 92.86% using the amorphous GST (a-GST) phase in the dielectric layer. The average absorption of a-GST is more in the crystalline GST (c-GST) phase in the proposed absorber. The change in the absorption peaks are observed using GST material in the terahertz region. The proposed broadband Jerusalem-shaped metasurface absorber is polarization insensitive due to its symmetrical structure.
原文链接:- NSTL
- Elsevier
Mo S.Guo K.Lao J.Liu G....
5页查看更多>>摘要：? 2021 Elsevier B.V.We investigate linear and nonlinear optical absorption coefficients (OACs) and refractive index changes(RICs) of a Morse quantum well when a quantum-sized metal nanoparticle is placed nearby. The exciton–plasmon coupling induces the modification of the energy interval and the relaxation rate of the Morse quantum well. The spontaneous decay rate of the Morse quantum well is also modified due to Purcell effect. These modification above reduce the magnitudes of the linear and nonlinear OACs and RICs of the Morse quantum well. More colorful results are demonstrated by controlling the size of the metal nanoparticle and the distance between the Morse quantum well and the metal nanoparticle. Our findings provide a way for manipulating the linear and nonlinear optical properties of the Morse quantum well.
原文链接:- NSTL
- Elsevier
Kebede M.T.Dillu V.Chauhan S.Devi S....
5页查看更多>>摘要：? 2021 Elsevier B.V.Bi1-xSmxFeO3 (BSFO, x = 0, 0.05, 0.10, 0.15, 0.20) nanoparticles were prepared through tartaric acid-modified sol-gel technique. X-ray diffraction and scanning electron microscopy provide phase purity and nanocrystalline behavior (29–92) nm of pristine and doped BFO nanoparticles. The crystallite sizes of the studied samples ranged from 19.64 nm to 12.26 nm. The Rietveld refinement of XRD data demonstrated a good configuration of change in the crystalline structure. Structural phase analysis by XRD suggested that structural transformation from rhombohedral structure (R3c space group) to orthorhombic structure (Pnma space group) is observed in Sm substituted BFO nanoparticles. The ferromagnetic properties increase up to x = 15 % in the samples with enhancing magnetization. A large component of the orthorhombic phase for x = 20 % sample results from a drastic decrease in the ferromagnetic property due to collinear antiferromagnetic ordering correlated with VSM and EPR studies.
原文链接:- NSTL
- Elsevier
