TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The process is a photochemical process, which takes place optionally using light such as artificial light, sun light (both in concentrated or diffused form), which produces thermal energy such as electric heating system, microwave system and earth heat, thermal energy or photochemical light source. The storage/discharge and/or absorption/desorption of hydrogen and/or oxygen takes place by silicide or its components, when the contact of the components with water is interrupted or ceased. The storage/discharge and/or absorption/desorption of oxygen simultaneously with hydrogen takes place by varying the amount of gases.Preferred Components: The silicide or its silicide components are metallic and/or non-metallic silicide such as boron silicide, carbon silicide and nitrogen silicide, titanium silicide (TiSi2, Ti5Si3), nickel silicide, iron silicide (FeSi2, FeSi), thallium silicide, boron silicide, silicium tetraboride, cobalt silicide, platinum silicide (PtSi, Pt2Si), manganese silicide, titanium carbosilicide, carbo silicide/poly-carbosilicide, silicium carbide/poly-silicium carbide, iridium silicide, nitro silicide, silicium nitride, zirconium silicide, tantalum silicide, vanadium silicide or chromium silicide, a silicon compound of formula RSix. The silicide or its compound contains at least a silicon atom with increased electron density. The silicon and its components is useful as catalyst. The wavelength of the light source and/or thermal energy source is 200-15000 nm. The light absorption of the silicide or its component is reinforced by coupling/complexing/attaching/binding with a coloring material or aggregation of coloring material such as perylene or its analogs. The silicide or its components are supported in a semi-conductor material with non-silicide structure e.g. ruthenium dioxide, manganese dioxide or tungsten trioxide. The silicide or its components are in immobilized form, if the components are applied or mounted on a electrical/electronic- or charge- conducting polymeric materials (e.g. polyamide, Makrolon (RTM: microporous glassy polymer), Plexiglas (RTM: acrylic resin)), surfaces, glass or its material. The silicide or its components are doped/alloyed by contacting with elementary and/or ionic/radical form of lithium, sodium, magnesium, potassium, calcium, aluminum, boron, carbon, nitrogen, silicium, titanium, vanadium, zirconium, yttrium, lanthanum, nickel, manganese, cobalt, gallium, germanium or lanthanides, where the amount of the elements are up to 50 wt.%.R = organic, metallic, organometallic and/or inorganic residue; andx = greater than 0. EXAMPLE - Titanium silicide (TiSi2 or Ti5Si3) (3 g) were stirred in water (200-400 ml), filtered and irradiated by solar radiation or artificial light source with emission maximum of 415 nm, 525 nm or 660 nm and emission volume of 300-550 nm, 490-600 nm and 610-700 nm to obtain hydrogen and oxygen (25 ml).