ADSORPTION PROPERTY OF NB (V) OXIDE GRAFTED ON SILICA-GEL SURFACE

Silica gel with a specific surface area S(BET) = 242 m2 g-1, particle sizes between 0.063 - 0.2 mm and 100 angstrom average pore diameter was chemically modified with Nb (V) oxide by the grafting process. The grafted Nb 3d3/2 and 3d5/2 binding energies are 210.3 and 207.5 eV, which have the same as those of Nb2O5. This material was able to immobilize ascorbic acid, forming a yellow surface complex by chemical bonding through the carbonyl oxygen atoms. The immobilized reagent was used to reduce Fe3+, Cu2+ and Cr2O7(2-).