The safe and efficient storage of hydrogen is widely recognized as one of the key technological challenges in the transition towards a hydrogen-based energy economy. Whereas hydrogen for transportation applications is currently stored using cryogenics or high pressure, there is substantial research and development activity in the use of novel condensed-phase hydride materials. However, the multiple-target criteria accepted as necessary for the successful implementation of such stores have not yet been met by any single material. Ammonia borane, NH3BH3, is one of a number of condensed-phase compounds that have received significant attention because of its reported release of approximately 12 wt% hydrogen at moderate temperatures (approximately 150 degrees C). However, the hydrogen purity suffers from the release of trace quantities of borazine. Here, we report that the related alkali-metal amidoboranes, LiNH2BH3 and NaNH2BH3, release approximately 10.9 wt% and approximately 7.5 wt% hydrogen, respectively, at significantly lower temperatures (approximately 90 degrees C) with no borazine emission. The low-temperature release of a large amount of hydrogen is significant and provides the potential to fulfil many of the principal criteria required for an on-board hydrogen store.

Azobenzene-derivatized alkanethiols have been used to form self-assembled monolayers on planar and colloidal gold substrates. Five derivatives were used allowing investigation of the effects of chain length, ω-functionality and a comparison of thiol versus disulfide. Single-component monolayer films, i.e., consisting only of the “azo”-derivatized thiols (disulfides), showed no evidence of photoswitching. However, “photoswitching” was observed in “mixed monolayers”, in self-assembled multilayers, and on nanoparticles coated with mixed monolayers. The photoswitching was observed using surface plasmon resonance on the planar samples and by UV−vis spectroscopy from nanoparticle solutions.

Small aromatic organothiol derivatives, with the structure HS±C 6 H 4 ±X, have been used to stabilise gold nanoparticles. The nature of the functional group, X, is important for controlling the relative strength of the particle±particle and particle±solvent interactions and hence in determining the physical properties of these systems (e.g. solubility). Particles were stabilised with different ligands for which X~OH, ±COOH, ±NH 2 , and ±CH 3 and thin ®lms of the particles were formed, by solution evaporation, on microelectrode patterned surfaces. The electronic behaviour indicates that conduction can be understood in terms of an activated electron tunnelling model. Finally, preliminary studies were carried out on the effect of exposure to different chemical vapours on the electronic transport properties.

We demonstrate, through structural refinement from synchrotron X-ray diffraction data, that the mechanism of the transformation between lithium amide and lithium imide during hydrogen cycling in the important Li-N-H hydrogen storage system is a bulk reversible reaction that occurs in a non-stoichiometric manner within the cubic anti-fluorite-like Li-N-H structure.