Search Results

You searched for all publications:

with publication states 'Published (Approved)'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

3 items found (0 items not approved), displaying all items.1

Instruments / Technical Area	Publication Details	Published
B18-Core EXAFS	Probing Mg intercalation in the tetragonal tungsten bronze framework V4Nb18O55 Ian D. Johnson , Gene Nolis , Kit Mccoll , Yimin A. Wu , Daisy Thornton , Linhua Hu , Hyun Deog Yoo , John W. Freeland , Furio Corà , Jeremy K. Cockcroft , Ivan P. Parkin , Robert F. Klie , Jordi Cabana , Jawwad A. Darr Inorganic Chemistry DOI: 10.1021/acs.inorgchem.0c01013 Diamond Proposal Number(s): [14239] Show Abstract ▼ Abstract: While commercial Li-ion batteries offer the highest energy densities of current rechargeable battery technologies, their energy storage limit has almost been achieved. Therefore, there is considerable interest in Mg batteries, which could offer increased energy densities in comparison to Li-ion batteries if a high-voltage electrode material, such as a transition-metal oxide, can be developed. However, there are currently very few oxide materials which have demonstrated reversible and efficient Mg2+ insertion and extraction at high voltages; this is thought to be due to poor Mg2+ diffusion kinetics within the oxide structural framework. Herein, the authors provide conclusive evidence of electrochemical insertion of Mg2+ into the tetragonal tungsten bronze V4Nb18O55, with a maximum reversible electrochemical capacity of 75 mA h g–1, which corresponds to a magnesiated composition of Mg4V4Nb18O55. Experimental electrochemical magnesiation/demagnesiation revealed a large voltage hysteresis with charge/discharge (1.12 V vs Mg/Mg2+); when magnesiation is limited to a composition of Mg2V4Nb18O55, this hysteresis can be reduced to only 0.5 V. Hybrid-exchange density functional theory (DFT) calculations suggest that a limited number of Mg sites are accessible via low-energy diffusion pathways, but that larger kinetic barriers need to be overcome to access the entire structure. The reversible Mg2+ intercalation involved concurrent V and Nb redox activity and changes in crystal structure, as confirmed by an array of complementary methods, including powder X-ray diffraction, X-ray absorption spectroscopy, and energy-dispersive X-ray spectroscopy. Consequently, it can be concluded that the tetragonal tungsten bronzes show promise as intercalation electrode materials for Mg batteries.	Jul 2020
B18-Core EXAFS	First example of protonation of Ruddlesden-Popper Sr2IrO4: a route to enhanced water oxidation catalysts Ronghuan Zhang , Paul E. Pearce , Vanessa Pimenta , Jordi Cabana , Haifeng Li , Daniel Alves Dalla Corte , Artem M. Abakumov , Gwenaëlle Rousse , Domitille Giaume , Michael Deschamps , Alexis Grimaud Chemistry Of Materials DOI: 10.1021/acs.chemmater.0c00432 Diamond Proposal Number(s): [12559] Show Abstract ▼ Abstract: Water electrolysis is considered as a promising way to store and convert excess renewable energies into hydrogen, which is of high value for many chemical transformation processes such as the Haber-Bosch process. However, to allow for the wide-spread of the polymer electrolyte membrane water electrolysis (PEMWE) technology, the main challenge lies in the design of robust catalysts for oxygen evolution reaction (OER) under acidic conditions since most of transition metal-based oxides undergo structural degradation under these harsh acidic conditions. To broaden the variety of candidate materials as OER cata-lysts, a cation-exchange synthetic route was recently explored to reach crystalline pronated iridates with unique structural properties and stability. In this work, a new protonated phase H3.6IrO4∙3.7H2O, prepared via Sr2+/H+ cation exchange at room temperature starting from the parent Ruddlesden-Popper Sr2IrO4 phase, is described. This is the first discovery of crystalline protonated iridate forming from a perovskite-like phase, adopting a layered structure with apex-linked IrO6 octahedra. Furthermore, H3.6IrO4∙3.7H2O is found to possess not only an enhanced specific catalytic activity, superior to that of other perov-skite-based iridates, but also a mass activity comparable to that of nanosized IrOx particles, while showing an improved catalytic stability owing to its ability to reversibly exchange protons in acid.	Mar 2020
	Understanding the defect chemistry of alkali metal strontium silicate solid solutions: insights from experiment and theory Ryan D. Bayliss , Stuart N. Cook , David O. Scanlon , Sarah Fearn , Jordi Cabana , Colin Greaves , John A. Kilner , Stephen Skinner Journal Of Materials Chemistry A 2 (42), 17919 - 17924 DOI: 10.1039/C4TA04299A Show Abstract ▼ Abstract: Recent reports of remarkably high oxide ion conduction in a new family of strontium silicates have been challenged. It has recently been demonstrated that, in the nominally potassium substituted strontium germanium silicate material, the dominant charge carrier was not the oxygen ion, and furthermore that the material was not single phase (R. D. Bayliss et. al., Energy Environ. Sci., 2014, DOI: 10.1039/c4ee00734d). In this work we re-investigate the sodium-doped strontium silicate material that was reported to exhibit the highest oxide ion conductivity in the solid solution, nominally Sr0.55Na0.45SiO2.775. The results show lower levels of total conductivity than previously reported and sub-micron elemental mapping demonstrates, in a similar manner to that reported for the Sr0.8K0.2Si0.5Ge0.5O2.9 composition, an inhomogeneous chemical distribution correlating with a multiphase material. It is also shown that the conductivity is not related to protonic mobility. A density functional theory computational approach provides a theoretical justification for these new results, related to the high energetic costs associated with oxygen vacancy formation.	Sep 2014

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User