Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userInsights of preferred growth, elemental and morphological properties of BN/SnO2 composite for photocatalytic applications towards organic pollutants
86
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Boron nitride (BN) has been explored these days because of its extraordinary optical, chemical and mechanical properties. BN is sensitive to its crystal structure that slight change in lattice parameters enormously change its properties. Present study deals with synthesis, characterization as well as photocatalytic applications of BN-based composite. When boron nitride was mixed with SnO2 having tetragonal crystal structure, dissociation into smaller sheets occurred and the material oriented to (102) plane. SnO2 particles attached both sides of BN sheets provided high surface area which make the material suitable for catalytic process. Presence of large number of active sites leads to the formation of hydroxyl radicals in BN/SnO2 composite which helps during degradation of organic and colourless pollutants i.e. methyl orange dye up-to ~92% under 7 minutes and salicylic acid in 40 minutes to ~82%. Results suggested that BN/SnO2 composite material possesses good capability for use in environmental as well as industrial applications.
rate research
Read More
Due to their characteristic geometry, TiO$_2$ nanotubes (TNTs), suitably doped by metal-substitution to enhance their photocatalytic properties, have a high potential for applications such as clean fuel production. In this context, we present a detailed investigation of the magnetic, electronic, and optical properties of transition-metal doped TNTs, based on hybrid density functional theory. In particular, we focus on the $3d$, the $4d$, as well as selected $5d$ transition-metal doped TNTs. Thereby, we are able to explain the enhanced optical activity and photocatalytic sensitivity observed in various experiments. We find, for example, that Cr- and W-doped TNTs can be employed for applications like water splitting and carbon dioxide reduction, and for spintronic devices. The best candidate for water splitting is Fe-doped TNT, in agreement with experimental observations. In addition, our findings provide valuable hints for future experimental studies of the ferromagnetic/spintronic behavior of metal-doped titania nanotubes.
A DFT study of the synthesized MAX phase Zr2SeC has been carried out for the first time to explore its physical properties for possible applications in many sectors. The studied properties are compared with prior known MAX phase Zr2SC. The structural parameters (lattice constants, volume, and atomic positions) are observed to be consistent with earlier results. The band structure and density of states (DOS) are used to explore the metallic conductivity, anisotropic electrical conductivity, and the dominant role of Zr-d states to the electrical conductivity. Analysis of the peaks in the DOS and charge density mapping (CDM) of Zr2SeC and Zr2SC revealed the possible variation of the mechanical properties and hardness among them. The mechanical stability has been checked using elastic constants. The values of the elastic constants, elastic moduli and hardness parameters of Zr2SeC are found to be lowered than those of Zr2SC. The anisotropic behavior of the mechanical properties has been studied and analyzed. Technologically important thermodynamic properties such as the thermal expansion coefficient, Debye temperature, entropy, heat capacity at constant volume, Gruneisen parameter along with volume and Gibbs free energy are investigated as a function of both temperature (0 to 1600 K) and pressure (0 to 50 GPa). Besides, the {Theta}D, minimum thermal conductivity (Kmin), melting point (Tm), and {gamma} have also been calculated at room temperature and found to be lowered for Zr2SeC compared to Zr2SC owing to their close relationship with the mechanical parameters. The value of the {Theta}D, Kmin, Tm, and TEC suggest Zr2SeC as a thermal barrier coating material. The dielectric constant (real and imaginary part), refractive index, extinction coefficient, absorption coefficient, photoconductivity, reflectivity, and loss function of Zr2SeC are computed and analyzed.
Hexagonal boron nitride (h-BN) is a promising material for implementation in spintronics due to a large band gap, low spin-orbit coupling, and a small lattice mismatch to graphene and to close-packed surfaces of fcc-Ni(111) and hcp-Co(0001). Epitaxial deposition of h-BN on ferromagnetic metals is aimed at small interface scattering of charge and spin carriers. We report on the controlled growth of h-BN/Ni(111) by means of molecular beam epitaxy (MBE). Structural and electronic properties of this system are investigated using cross-section transmission electron microscopy (TEM) and electron spectroscopies which confirm good agreement with the properties of bulk h-BN. The latter are also corroborated by density functional theory (DFT) calculations, revealing that the first h-BN layer at the interface to Ni is metallic. Our investigations demonstrate that MBE is a promising, versatile alternative to both the exfoliation approach and chemical vapour deposition of h-BN.
We report the stability and electronic structures of the boron nitride nanotubes (BNNTs) with diameters below 4 A by semi-empirical quantum mechanical molecular dynamics simulations and ab initio calculations. Among them (3,0), (3,1), (2,2), (4,0), (4,1) and (3,2) BNNTs can be stable well over room temperature. These small BNNTs become globally stable when encapsulated in a larger BNNT. It is found that the energy gaps and work functions of these small BNNTs are strongly dependent on their chirality and diameters. The small zigzag BNNTs become desirable semiconductors and have peculiar distribution of nearly free electron states due to strong hybridization effect. When such a small BNNT is inserted in a larger one, the energy gap of the formed double-walled BNNT can even be much reduced due to the coupled effect of wall buckling difference and NFE-pi hybridization.
Recently, nanolaminated ternary carbides have attracted immense interest due to the concomitant presence of both ceramic and metallic properties. Here, we grow nanolaminate Ti3AlC2 thin films by pulsed laser deposition on c-axis-oriented sapphire substrates and, surprisingly, the films are found to be highly oriented along the (103) axis normal to the film plane, rather than the (000l) orientation. Multiple characterization techniques are employed to explore the structural and chemical quality of these films, the electrical and optical properties, and the device functionalities. The 80-nm thick Ti3AlC2 film is highly conducting at room temperature (resistivity of 50 micro ohm-cm), and a very-low-temperature coefficient of resistivity. The ultrathin (2 nm) Ti3AlC2 film has fairly good optical transparency and high conductivity at room temperature (sheet resistance of 735 ohm). Scanning tunneling microscopy reveals the metallic characteristics (with finite density of states at the Fermi level) at room temperature. The metal-semiconductor junction of the p-type Ti3AlC2 film and n-Si show the expected rectification (diode) characteristics, in contrast to the ohmic contact behavior in the case of Ti3AlC2 on p-Si. A triboelectric-nanogenerator-based touch-sensing device, comprising of the Ti3AlC2 film, shows a very impressive peak-to-peak open-circuit output voltage of 80 V. These observations reveal that pulsed laser deposited Ti3AlC2 thin films have excellent potential for applications in multiple domains, such as bottom electrodes, resistors for high-precision measurements, Schottky diodes, ohmic contacts, fairly transparent ultrathin conductors, and next-generation biomechanical touch sensors for energy harvesting.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
