MONOCATIONIC CLAY-MINERAL-SEMICONDUCTOR-METAL-OXID AND/OR HYDROXID NANOCOMPOSITIONS, PROCESS FOR PRODUCING THEM AND APPLYING THEM FOR PHOTOOXIDATION DECOMPOSING OF ENVIRONMENTALLY HARMFUL ORGANIC MATERIALS

摘要

Nano-composites used in environmental protection are mono-cationic clay-mineral stabilized semi-conductor metal oxide and/or hydroxide compositions having a specific surface of 10-400 m2/g and a metal oxide concentration of 10-70% calculated on the solids content of the clay mineral. The method of nano-composite preparation contains following features: (i) A solution of at least one metallic-salt is added to an aq. clay-mineral suspension at a given pH value. (ii) followed by the addition of a sol of a semiconductor metal oxide/hydroxide. (iii) sedimented-out nano-composite is separated from the disperse medium and is dried at 80-120[deg]C and optionally (iv) the nano-composite is calcined at 320-450[deg]C and/or (v) it is comminuted.