Abstract
Water splitting is becoming one of the most important processes for producing green fuel hydrogen. Among various materials, alumina provides the best surface for water splitting to generate green energy hydrogen. Therefore, radiation-catalytic and radiation-thermocatalytic activities of the polymorphic forms of Al2O3 (alpha-, delta-, gamma-) in the water decomposition process were studied at various temperatures. It is established that gamma-Al2O3 has relatively high radiation-catalytic properties in the process of water decomposition. The maximum yields of the radiation-chemical molecular hydrogen at 873 K for 30 hrs were 4.5, 5.8, and 7.0 N(H-2)x10(-18) molecules/g for alpha-, delta- and gamma-Al2O3; indicating the best performance of gamma-Al2O3. The pattern of accumulation of localized states of non-equilibrium charge carriers in polymorphic forms of gamma-Al2O3 was determined. Furthermore, the proposed mechanisms of energy transfer and lengths of energy transfer in radiation-heterogeneous processes of water decomposition were determined. The developed method may be used to produce hydrogen fuel on a large scale.