Kinetics of Hydrogen Generation from Si Nanostructures and Si Powder

In present work we compare kinetics and efficiency of hydrogen release from stain etched porous silicon (average size of 3-100 nm), silicon powder obtained from waste of the metallurgical silicon with different chemical content. The influence of powder fraction by particles size and mode of treatment on the amount of bonded hydrogen have been studied. Size of silicon nanocrystallites was controlled by DLS method, the chemical composition of metallurgical silicon was analysed by Energy-dispersive X-ray spectroscopy. Metallurgical silicon was processed in a blender, milled, filtered and centrifuged. This allowed us to obtain crystallites measuring 100-1000 nm. The H2 release intensity in the reaction of PS with water and a catalyst can be controlled by changing the catalyst concentration and temperature. The presence of impurities (iron, carbon, aluminium, calcium, cerium and others) in metallurgical silicon influences the yield of hydrogen generation. Physicochemical processes associated with the catalytic properties of additives in metallurgical silicon to increase the yield of hydrogen are discussed.