The next-generation of batteries need be both energy dense and environment friendly. Lithium sulfur batteries (LSBs) satisfy both criteria but their practical implementation is marred by the highly resistive nature of sulfur. Carbon-based cathodes play a vital role in mitigating the issue because their high conductivity allows for effective electron transfer during electrochemical cycling. Synthesis and electrochemical evaluation of carbon-based cathodes from two different sources for LSBs was carried out. Herein, two kinds of carbon, namely bio-derived carbon from coconut shells (CC500) and N-doped carbon (NC) from polyacrylonitrile fibers were synthesized and sulfur was incorporated via the melt diffusion route. The composites are characterized by PXRD and TGA, which determined 80 wt

Radioactive cesium (137Cs+) is one of the most hazardous fission products in the radioactive liquid waste due to its large inventory, long half-life (t1/2 ∼30 years) and high environmental mobility. It is of vital importance to retain 137Cs+ within the waste repository boundary. Different clay minerals have shown great potential for scavenging metal ions from earth's critical zone. However, till date the molecular level retention mechanisms remain partly understood. Initial characterization of vermiculite clay was carried out by FTIR, SEM-EDX and PXRD. Adsorption of 137Cs+ from aqueous solution on vermiculite, under batch equilibrium experimental condition has been investigated. Different adsorption parameters were studied. Effect of Initial concentration of vermiculite doses was investigated. Adsorption experiment was carried out under different temperature and pH of the medium. Thermodynamical parameter of the adsorption process was evaluated. The effect of 137Cs+incorporation and solutions were analysed quantitatively using ICP-OES. 137Cs+ions loaded vermiculite clay was characterized by FTIR, SEM-EDX and PXRD to study the fate of the clay after adsorption. The retention of 137Cs+ ions inside vermiculite matrix was established by x-ray elemental mapping. It was confirmed that the Cs ions replaced the Mg ions from the crystal. The effect of 137Cs+adsorption on the structure of the clay minerals vermiculite in suspensions was elucidated. We proposed molecular level interaction of 137Cs+ions with the clay and described the mechanism of 137Cs+ions retention in clay.

Efficient and selective sequestration of pertechnetate ions (99TcO(4)(-)) from nuclear low-level waste (LLW) solution is very much desirable for the safe treatment of radioactive liquid waste. However, the separation of specific radionuclides from competitors is a huge challenge in separation science. In the nuclear fuel cycle, 99TcO(4)(-) is one of troublesome fission products due to long half-life, large inventory in spent fuel, significant radiation hazards, and high environmental mobility of 99TcO(4)(-) ions. Recently, the metal-organic framework (MOFs) has shown significant potentials toward 99 TcO4- removal. So far, most of the studies were reported using ReO4- ions, an inactive surrogate of 99TcO(4)(-) ions, and very few MOF materials are applied for real-time 99TcO(4)(-) sequestration from nuclear waste solution in the presence of extreme conditions. Herein, we report 99TcO(4)(-) ion removal from low-level liquid nuclear waste solution using zirconium-based metal-organic framework UIO-66-NH2. The material has exhibited fast kinetics and record selectivity toward 99TcO(4)(-)ions, making the adsorbent highly promising. [Graphics] .

Radioactive cesium (137Cs+) is one of the most hazardous fission products in the radioactive liquid waste due to its large inventory, long half-life (t1/2 ~30 years) and high environmental mobility. It is of vital importance to retain 137Cs+ within the waste repository boundary. Different clay minerals have shown great potential for scavenging metal ions from earth’s critical zone. However, till date the molecular level retention mechanisms remain partly understood. Initial characterization of vermiculite clay was carried out by FTIR, SEM-EDX and PXRD. Adsorption of 137Cs+ from aqueous solution on vermiculite, under batch equilibrium experimental condition has been investigated. Different adsorption parameters were studied. Effect of Initial concentration of vermiculite doses was investigated. Adsorption experiment was carried out under different temperature and pH of the medium. Thermodynamical parameter of the adsorption process was evaluated. The effect of 137Cs+ incorporation and solutions were analysed quantitatively using ICP-OES. 137Cs+ ions loaded vermiculite clay was characterized by FTIR, SEM-EDX and PXRD to study the fate of the clay after adsorption. The retention of 137Cs+ ions inside vermiculite matrix was established by x-ray elemental mapping. It was confirmed that the Cs ions replaced the Mg ions from the crystal. The effect of 137Cs+ adsorption on the structure of the clay minerals vermiculite in suspensions was elucidated. We proposed molecular level interaction of 137Cs+ ions with the clay and described the mechanism of 137Cs+ ions retention in clay

Dielectric studies were carried out on Nd2CuTiO6 samples prepared by high temperature solid-state reaction followed by annealing under different oxygen partial pressures. X-ray diffraction studies revealed that the orthorhombic (Pnma) structure of Nd2CuTiO6 is retained in all the samples. The room temperature permittivity at 100Hz was found to be about 200 in the air-annealed sample, and it increased considerably to about 3000 upon annealing in argon atmosphere. The electrical conductivity in the argon-annealed compound was found to be an order of magnitude higher than that for the air-annealed sample. On annealing in oxygen, both permittivity and electrical conductivity of the sample were found to be significantly reduced. The variation in dielectric properties could be attributed to the induction or annihilation of mixed valence state of copper and oxygen vacancies, which was supported by X-ray photoelectron and diffuse reflectance spectroscopy data. The analysis of temperature and frequency dependent conductivity and dielectric data showed that the overlapping large polaron tunnelling (OLPT) mechanism is responsible for the observed dielectric relaxations and conduction. The observed systematic dependence of properties on the oxygen partial pressure of the annealing environment suggests a simple method to tune the electrical properties of Nd2CuTiO6.

We have synthesized bismuth telluride compound using mechanical alloying and hot press sintering method. The phase formation, crystal structure was evaluated by X-ray diffraction and Raman spectroscopy. The scanning electron microscopy images indicated sub-micron sized grains. We observed low value of thermal conductivity 0.39 W/mK at room temperature as a result of grain size reduction by increasing deformation. The performance of the samples can be improved by reducing the grain size, which increases the grain boundary scattering.