A novel material based on niobia (Nb2O5) was synthesized to oxidize an organic compound in aqueous medium in the presence of H2O2 after chemical modifications. Niobia was modified by doping with tungsten and also treating with H2O2 in order to maximize the oxidative properties of this oxide. The analysis of the products from methylene blue dye oxidation with electrospray ionization mass spectrometry (ESI-MS) showed that the dye was successively oxidized to different intermediate compounds. The successive hydroxylation during this oxidation strongly suggests that highly reactive hydroxyl radicals are generated involving H2O2 on the W-doped niobia grain surface. These results strongly suggest that the H2O2 can regenerate in situ the peroxo group remaining active the system.
niobia; tungsten; catalytic oxidation; organic contaminant
