Electrospun zeolite-templated carbon composite fibres for hydrogen storage applications

Research on Chemical Intermediates - The current study explored the application of the electrospinning technique to produce multi-hierarchical composites for hydrogen storage applications....     

Preliminary studies in the electrodeposition of PbSe/PbTe superlattice thin films via electrochemical atomic layer deposition (ALD)

This paper concerns the electrochemical growth of compound semiconductor thin film superlattice structures using electrochemical atomic layer deposition (ALD). Electrochemical ALD is the electrochemical analogue of atomic layer epitaxy (ALE) and ALD, methods based on nanofilm formation an atomic layer at a time, using surface-limited reactions. Underpotential deposition (UPD) is a type of electrochemical surfaced-limited reaction used in the present studies for the formation of PbSe/PbTe superlattices via electrochemical ALD. PbSe/PbTe thin-film superlattices with modulation wavelengths (periods) of 4.2 and 7.0 nm are reported here. These films were characterized using electron probe microanalysis, X- ray diffraction, atomic force microscopy (AFM), and infrared reflection absorption measurements. The 4.2 nm period superlattice was grown after deposition of 10 PbSe cycles, as a prelayer, resulting in an overall composition of PbSe0.52Te0.48. The 7.0 nm period superlattice was grown after deposition of 100 PbTe cycle prelayer, resulting for an overall composition of PbSe0.44Te0.56. The primary Bragg diffraction peak position, 2theta, for the 4.2 superlattice was consistent with the average (111) angles for PbSe and PbTe. First-order satellite peaks, as well as a second, were observed, indicating a high-quality superlattice film. For the 7.0 nm superlattice, Bragg peaks for both the (200) and (111) planes of the PbSe/PbTe superlattice were observed, with satellite peaks shifted 1 degrees closer to the (111), consistent with the larger period of the superlattice. AFM suggested conformal superlattice growth on the Au on glass substrate. Band gaps for the 4.2 and 7.0 nm period superlattices were measured as 0.48 and 0.38 eV, respectively.     

Synthesis of a hybrid MIL-101(Cr)/ZTC composite for hydrogen storage applications

Metal–organic frameworks (MOFs) hybrid composites have recently attracted considerable attention in hydrogen storage applications. In this study a hybrid composite of zeolite templated carbon (ZTC) and Cr-based MOF (MIL-101) was synthesised by adding the templated carbon in situ during the synthesis of MIL-101(Cr). The obtained sample was fully characterized and hydrogen adsorption measurements performed at 77 K up to 1 bar. The results showed that the surface areas and the hydrogen uptake capacities of individual MIL-101 (2552 m² g^?1, 1.91 wt%) and zeolite templated carbon (2577 m² g^?1, 2.39 wt%) could be enhanced when a hybrid MIL-101(Cr)/ZTC composite (2957 m² g^?1, 2.55 wt%) was synthesized. The procedure presents a simple way for enhancement of hydrogen uptake capacity of the individual Cr-MOF and templated carbon samples.