New directions in nanostructured materials prepared by solution combustion synthesis

Materials for the future require high efficiency in both design and applications. In order to produce materials of this nature, a deep knowledge on the synthesis-structure-properties relationships is mandatory. Solution Combustion Synthesis (SCS) is a well-known preparation method based on the concepts of both propellant chemistry and sol-gel chemistry, where a self-sustained reaction between a combustion fuel and an oxidant occurs in the presence of metal precursors [F. Deganello et al, J. Eur. Ceram. Soc., 2009]. SCS is essentially governed by the fuel type and concentration. This presentation is on new directions in the SCS for the preparation of nanostructured materials for energy and environment. Highly conducting perovskite cathodes for intermediate temperature solid oxide fuel cells are fabricated by optimization of the fuel mixture [F. Deganello et al, Mater. Renew. Sust. Energy, 2013]. The combustion fuel is also able to influence the sintering properties and the conductivity of ceria-based electrolytes. Efficient perovskite photocatalysts are produced when the combustion fuel is derived from bio-based wastes, encouraging the reuse of wastes for environmental protection. A selection of the fuel-type or carbon source, followed by inert gas thermal treatment, allows to obtain perovskite-carbon nanocomposites. These materials find application as bifunctional electrodes for Zn-air batteries, where perovskite and carbon are in good nanoscale contact, favouring better electrochemical performances. Finally, soft and hard templating methodologies are combined in the Soft-Hard Templating approach (SHT) to create high surface area perovskite-based nanopowders for catalysis applications [F. Deganello et al., J. Mater. Chem. A, 2014].