Hydrogen-storage properties of MgH2–10Ni–2NaAlH4–2Ti prepared by reactive mechanical grinding

A sample of 86 wt% MgH₂–10 wt% Ni–2 wt% NaAlH₄–2 wt% Ti (named MgH₂–10Ni–2NaAlH₄–2Ti) was prepared by reactive mechanical grinding. Activation of the sample was not required at 573 K. At the first hydriding–dehydriding cycle (n = 1), the sample absorbed more than 5 wt% H at 573 K under 12 bar H₂ for 60 min. The hydriding rate increased as the temperature increased from 423 K to 553 K. MgH₂–10Ni–2NaAlH₄–2Ti showed quite high hydridng rates at relatively low temperatures of 423 K and 473 K under 12 bar H₂, absorbing 4.02 wt% H for 60 min at 473 K.     

Synthesis and structural,morphological, compositional,optical and electrical properties of DBSA-doped PPy–WO3 nanocomposites

Synthesis of DBSA-doped PPy–WO₃ (organic–inorganic) nanocomposites, using a novel approach, has been proposed, and further envisaged for their structural, compositional, morphological, optical and electrical properties. DBSA-doped PPy–WO₃ nanocomposites demonstrate superior above mentioned properties than their counterparts i.e. either PPy or WO₃. The XRD spectra of nanocomposites supported to conclude that both i.e. PPy and DBSA have no impact on the crystallinity of WO₃ nanoparticles. The chemical structure of DBSA-doped PPy–WO₃ nanocomposites have been elucidated using FTIR spectra. The morphologies and surface roughnesses of the DBSA-doped PPy–WO₃ nanocomposites were confirmed using scanning electron microscope and atomic force microscope images, respectively. Interconnected type morphology and 13 nm average surface roughness were confirmed for DBSA doped PPy–WO₃ hybrid nanocomposites. The EDX and XPS analyses evidence that, the formation of DBSA doped PPy–WO₃ hybrid nanocomposites without any elemental impurities. The absorption peak of DBSA-doped PPy–WO₃ nanocomposites shift towards the lower wavelength side as compared to the PPy–WO₃ (50%) hybrid nanocomposites. Anionically charged sulfonate group which is supposed to stabilize doped state of the DBSA-PPy–WO₃ nanocomposites, may be responsible for this shift. The dc electrical conductivity of DBSA-doped PPy–WO₃ nanocomposites increases as the content of DBSA is increased from 10 to 50% this could be accounted for by the generation of conduction path through the PPy–WO₃ nanocomposites as DBSA has anionic surfactant nature by preventing an agglomeration of functional material.