Functional materials derived from the schafarzikite mineral framework

Many inherent problems need to be overcome if we are to approach an energy framework that is both clean and sustainable. Although progress is being made, it is likely that solutions will rely on new concepts in the design of materials rather than improvements to existing materials. This view provides the rationale behind the proposed research: based on preliminary exciting findings, we will extend our studies of a class of materials with unique structural features that have never been fully exploited - nor even fully explored. The research focuses on a mineral, schafarzikite, and our preliminary studies have been directed towards introducing functionality to provide useful properties. This proposal emanates from two highly exciting findings:
1) we have been able to insert anions into channels within the schafarzikite framework;
2) we have discovered a schafarzikite material that contains a low-dimensional copper oxide framework that is ferromagnetic.

The first discovery suggests that this structure could make an important contribution to aspects of energy storage, both for new electrode materials and new electrolytes. It is our objective to characterise fully these new materials and screen them for use as advanced materials in these areas. This programme, and possible subsequent commercialisation, will be assisted by a collaboration with Johnson Matthey.

The second research finding is of academic interest because ferromagnetic oxides are quite rare. However, added interest attaches to the fact that low dimensional copper oxides provided the basis for the High-Tc superoconducting materials that superconduct at temperatures up to 133 K. However, all these materials have antiferromagnetic parent phases, and this antiferromagnetism is likely to be inportant in the superconductivity mechanism. The chemical manipulation of this particular material to introduce electronic conductivity is therefore a major objective of the programme. We are not aware of any studies that relate to elecronic conduction in copper oxide materials with an inherent ferromagnetic ground state.

Materials with the perovskite structure have been studied extensively and their properties have resulted in applications in many areas, including electrodes and electrolytes in electrochemical devices. Although structurally very different from perovskites, functionalising their properties is conceptually similar to that which can be achieved for the perovskite system: cation substitutions at one site can be used to tune the functional properties at the other. However, there has been very little previous research that has focused on this structure. We will therefore be vigilant to recognise other new features that are likely to become apparent during the programme but are not included in the specific targets above.

The synthetic aspects of the programme of work will be informed by predictions of suitable chemical targets that have been determined by theoretical calculations relating to the stabilities of possible chemical compositions.

New materials for clean and sustainable energy are crucial in our search for solutions to problems relating to the decline in fossil fuel reserves and the increasing impact that current energy usage has on ecology, e.g. climate. Our proposal addresses the synthesis of materials with a structure that has received very little prior attention but has characteristics that appear attractive for many energy applications. For example, efficient batteries for electric vehicles would provide a clean method for the storage of energy, and systems are currently under commercial development. The materials at the focus of this programme have exciting potential that could address problems with both electrodes and electrolytes in such devices. UK industry is in a position to exploit these advances, and has already shown serious interest in the proposal. In addition, the lack of previous study of these materials suggests that a large raft of other interesting properties will be discovered. In fact our preliminary studies have also revealed a new low-dimensional ferromagnetic oxide; studies will now be extended to chemically modified materials in order to assess their potential to display interesting electronic, and possibly superconducting, behaviour.

The materials under investigation have one-dimensional channels running through their structures. We have demonstrated that these channels can act as hosts to small molecules and, in this respect, we believe they have unique characteristics which might be relevant to a range of catalytic and electrocatalytic properties. We expect this work to identify a number of further promising avenues for investigation into this portfolio of new materials.

The PDRA and PhD student who will be involved in this programme will receive high quality academic training in the synthesis, characterisation and modelling of new materials. In addition, we also expect them to organise and participate actively in two workshops for school students. The subject area will be relevant to materials for energy-related applications, and they will deliver talks. This will develop their organisational and communication skills, important for subsequent careers. They will also deliver presentations within the School of Chemistry, as part of our training schemes, and externally at conferences as a contribution to the academic dissemination of our results. A third workshop will precede a seminar from an external academic researcher, and will provide interaction between school students and young researchers in the Materials Chemistry Group at Birmingham. This will foster enthusiasm in the school students to encourage them to apply for higher education in relevant scientific disciplines, and to make a contribution to the future economic competitiveness of the UK.