Molybdenum Sulfide Nanoflowers as Electrodes for Efficient and Scalable Lithium-Ion Capacitors.

Hybrid supercapacitors (HSCs) bridge the unique advantages of batteries and capacitors and are considered promising energy storage devices for hybrid vehicles and other electronic gadgets. Lithium-ion capacitors (LICs) have attained particular interest due to their higher energy and power density than traditional supercapacitor devices. The limited voltage window and the deterioration of anode materials upsurged the demand for efficient and stable electrode materials. Two-dimensional (2D) molybdenum sulfide (MoS2) is a promising candidate for developing efficient and durable LICs due to its wide lithiation potential and unique layer structure, enhancing charge storage efficiency. Modifying the extrinsic features, such as the dimensions and shape at the nanoscale, serves as a potential path to overcome the sluggish kinetics observed in the LICs. Herein, the MoS2 nanoflowers have been synthesized through a hydrothermal route. The developed LIC exhibited a specific capacitance of 202.4 F g-1 at 0.25 A g-1 and capacitance retention of >90 % over 5,000 cycles. Using an ether electrolyte improved the voltage window (2.0 V) and enhanced the stability performance. The ex-situ material characterization after the stability test reveals that the storage mechanism in MoS2-LICs is not diffusion-controlled. Instead, the fast surface redox reactions, especially intercalation/deintercalation of ions, are more prominent for charge storage.

Influence of CuO/MgO ratio on the gene expression, cytocompatibilty, and antibacterial/anticancerous/analgesic drug loading kinetics for (15-x) CuO-xMgO-10P2 O5 -60SiO2 -10CaO-5ZnO (2.5 ≤ x ≤ 12.5) mesoporous bioactive glasses.

In the present study, novel mesoporous bioactive glasses (MBGs) (15-x)CuO-xMgO-10P2 O5 -60SiO2 -10CaO-5ZnO (2.5 ≤ x ≤ 12.5, varying in steps of 2) are synthesized using the sol-gel technique. The structural phases of the glasses/glass ceramics were studied by XRD. The pH variation and simulated body fluids (SBF) studies demonstrated the in-vitro bioactivity of all the MBGs. MBGs possess surface area variation between 98.22 and 442.41 cm2 /g. The pore size of MBGs lies in the range of 5.8-8.8 nm. The cytotoxicity assays were conducted for MG63 human osteosarcoma cell line depicting non-toxic behavior of all MBGs at 7.8125 µg/ml. In addition to this, the effect of the magnesium on the gene expression was also investigated using reverse transcription-polymerase chain reaction (RT-qPCR). The MBGs were loaded with the antibacterial (vancomycin/amoxicillin), anticancerous (doxorubicin), and analgesic (Iburofen) drugs. Ibuprofen and amoxicillin drugs were almost fully loaded in all the MBGs, whereas doxorubicin and vancomycin drugs illustrated variation in loading with decreasing copper content. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2116-2130, 2018.

Thermal and structural studies of carbon coated Mo2C synthesized via in-situ single step reduction-carburization.

Carbon coated nano molybdenum carbide (Mo2C) has been synthesized at 800 °C through single step reduction route using molybdenum trioxide (MoO3) as a precursor, polypropylene (P.P) as a carbon source and magnesium (Mg) as a catalyst in an autoclave. The synthesized samples were characterized by X-ray diffraction (XRD), thermal analysis techniques (TG/DTA/DTG), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Williamson- Hall (W-H) analysis has been done to estimate various parameters like strain, stress and strain energy density. Multi-stage kinetic analysis of the product phase has been studied to establish the nature of the thermal decomposition. Coats-Redfern method applied to determine the mechanism involved in the decomposition of the product phase shows that initial and final stage follow F1 mechanism whereas middle stage follow F3 mechanism. The activation energy (E a) and pre-exponential factor (A) has also been determined. The morphological studies shows that the particles have partially spherical/faceted shape, with carbon coated having wide particle size distribution. The surface chemistry and surface area analysis were studied by X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmet-Teller (BET), respectively. The formation mechanism of carbon coated Mo2C nano particles has been predicted based on the XRD, TG/DTA & DTG and microstructural results.