CATALYSTS ON THE BASE OF LAYERED OXIDES FOR THE DECOMPOSITION OF WATER AND WASTE COMPOUNDS
Advancing the chemical engineering fundamentals
Catalysis (T2-13P)
Keywords: Photocatalysts, photocatalytic reactions, water splitting, hydrogen energy, layered materials
Photocatalytic water splitting reaction has received much attention as a method for solar energy conversion into chemical energy because of its potential to directly obtain clean hydrogen. The construction of an efficient artificial photosynthesis system for solar energy conversion and storage is one of the fascinating goals to solve the global energy problem. Application of photocatalytic reactions is much perspective for sterilization of water for different waste products.
Nowadays some technological methods are not useful in practice, because there are no proper materials and substances. There is considerable interest at present in layered oxides. A variety of mixed metal oxides such as perovskite-type and another layered structures, have been extensively studied as substances able to decompose water under irradiation. Use of layered materials is especially interesting because of the possibility of modifying the chemical composition as well as microstructure by means of ion-exchange or intercalation, which is useful for designing photocatalysts based on semiconducting metal oxide sheets.
Report focuses on the structural design and photocatalytic properties of materials based on perovskite-type layered oxides. We consider oxides with photocatalytic activity for the process of water splitting and decomposition of waste compounds.
The preparation potential photocatalytic materials, investigate their structure, phase stability and photocatalytic properties are the main aspects of presentation. This provides understanding of the structural and electronic factors responsible for photo-initiated decomposition processes in the interlayer space of layered structures. The knowledge of these properties would open a route towards new materials for the solving environmental and ecological problems.
The possibilities of layered oxides and their derivatives with interplay between layered type of structure, cationic ordering, electric polarization are not comprehensively studied. A new way to improve photocatalytic activity for the decomposition of compounds by introduction of ordered perovskites is related to creating ordered arrangements of cations with local dipoles. The analysis covers wide range of oxides which belongs to layered perovskite-type structures (Ruddlesden-Popper, Dion-Jacobson and Aurivillius phases with various thickness of perovskite slabs), investigation of oxides with variable anisotropy of structure and chemical content (titanates, tantalates, niobates, aluminates), kinetics of photocatalytic processes, methods of synthesis and using photocatalysts at practical conditions.
Acknowledgements. Authors are grateful for the financial support of the Federal Education Agency of Russia. The present contribution was developed within the framework of the project "Innovative educational environment in the classical university" by the St. Petersburg State University.
Presented Wednesday 19, 13:30 to 15:00, in session Catalysis (T2-13P).
