Study on Enhancing the Thermoelectric Properties of Ti2CrSn Alloys

Based on the Hg2CuTi structure, the full-Heusler alloy Ti2CrSn, with a ground state band gap of semiconductor, is a thermoelectric material with potential applications. Through preparing Ti2CrSn1−xAlx (x = 0, 0.05, 0.1, 0.15, 0.2) series bulk materials via arc melting, the effects of the electrical and thermal transport properties of Ti2CrSn series alloys were investigated, and different Al doping on the phase structure, the microscopic morphology, and the thermoelectric properties of Ti2CrSn were examined. The results show that the materials all exhibit characteristics of p-type semiconductors at the temperature range of 323 to 923 K. Al elemental doping can significantly increase the Seebeck coefficient and reduce the thermal conductivity of the materials. Among them, the sample Ti2CrSn0.8Al0.2 obtained a maximum value of 5.03 × 10−3 for the thermoelectric optimal ZT value at 723 K, which is 3.6 times higher than that of Ti2CrSn.

Phase, Microstructure, Thermochromic, and Thermophysical Analyses of Hydrothermally Synthesized W-Doped VO2 Nanopowder

Vanadium dioxide (VO2) has great potential as an intelligent architectural glazing system as it can control the amount of light, heat, and solar energy relative to the temperature in the environment. However, the applicability of VO2 for commercial use is yet to be realized because its phase transition temperature (τc) of ∼68°C is too high for use in buildings. A proven strategy to lower its τc is by elemental doping. Hence, in this study, hydrothermal synthesis of nanostructured VO2 was carried out with the introduction of tungsten (W) as a dopant. Furthermore, the effects of W doping on the structural, thermochromic, and thermophysical properties of VO2 were examined. Using X-ray diffraction (XRD), it was found that the addition of W atoms affected the VO2 lattice since the crystal structure of VO2 was changed from monoclinic to tetragonal rutile. Subsequently, this influenced the thermochromic behavior of the prepared VO2. Based on the differential scanning calorimetry (DSC), doping with tungsten resulted in a significant decrease in τc from 66.47°C to as low as 31.64°C. Moreover, W doping affected the thermophysical properties of the samples. Accordingly, an abrupt increase in the thermal conductivities of the doped samples was observed across the transition temperature.

Various Material Development Strategies for Suitable Catalysts of Photo Catalytic Water Splitting to Green Fuel H2:A Critical Review

Fossil fuels are the most substantial & extensively used sources of energy for today’s world. Simultaneously, the unconscious exposure of toxic pollutants and green-house gases allied with fossil energy is not viable with contexture. Solar energy were treated as an auspicious source of energy from ancient age because of its richness & cleanness. But problem arises in its capture, storage, transformation, and distribution. That’s why scholars are trying to convert this renewable light energy to a user friendly and viable form of energy. By analyzing recent studies on H2 fuel it is considered as most lucrative choice for clean and sustainable fuel with high calorific value & zero pollution. This review offers an overview of most recent advancement in development of photo-catalyst for solar water splitting which is treated as a promising Green-Harvesting technique among all H2 generation techniques. Here we discussed about various catalyst development techniques especially about doping techniques, reactor design and light scattering/trapping systems.We found that among all doping is a promising technique and a lots of study have been done on this technique than others like as Hetero junction, Dye sensitization, modification of surface or nanostructure formation. Hence we concluded with the decision that, more research are needed on hetero junction and nanostructure formation along with elemental doping.

Tuning the Dielectric and Microwaves Absorption Properties of N-Doped Carbon Nanotubes by Boron Insertion

It is of great significance to regulate the dielectric parameters and microstructure of carbon materials by elemental doping in pursuing microwave absorption (MA) materials of high performance. In this work, the surface electronic structure of N-doped CNTs was tuned by boron doping, in which the MA performance of CNTs was improved under the synergistic action of B and N atoms. The B,N-doped carbon nanotubes (B,N-CNTs) exhibited excellent MA performance, where the value of minimum reflection loss was −40.04 dB, and the efficient absorption bandwidth reached 4.9 GHz (10.5–15.4 GHz). Appropriate conductance loss and multi-polarization loss provide the main contribution to the MA of B,N-CNTs. This study provides a novel method for the design of CNTs related MA materials.

Bifunctional electrochemical properties of La0.8Sr0.2Co0.8M0.2O3-δ (M= Ni, Fe, Mn, Cu): efficient elemental doping based on structural and pH-dependent study

Perovskite oxides with a low cost and high catalytic activity are considered as suitable candidate for oxygen evolution reaction (OER)/oxygen reduction reaction (ORR), whereas most of them favor only either...