Sol-Gel Obtaining of TiO[sub.2]/TeO[sub.2] Nanopowders with Biocidal and Environmental Applications

TiO[sub.2]/TeO[sub.2] powders were obtained by an aqueous sol-gel method. Telluric acid (H[sub.6]TeO[sub.6]) and titanium butoxide were used as precursors. The as-prepared gel was step-wisely heated in the temperature range 200-700 °C and subsequently characterized by XRD, IR, and UV-Vis analysis and SEM. Mixtures containing TiO[sub.2] (anatase), α-TeO[sub.2] (paratellurite), and TiTe[sub.3]O[sub.8] were established by XRD as final products, depending on heating temperature. The thermal stability of the obtained gels in the temperature range 100-400 °C was investigated. It was found by IR spectroscopy that the samples heated up to 300-400 °C consist mainly of an organic-inorganic amorphous phase which is transformed into an inorganic one above these temperatures. The microstructure of the gels was verified by scanning electron microscopy (SEM). The photocatalytic degradation of the synthesized nanopowders toward Malachite green organic dye (MG) was examined in order to evaluate the potential applications for environmental remediation. The prepared TiO[sub.2]/TeO[sub.2] samples showed up to 60% decoloration efficiency after 120 min exposure to UV-light. The composition exhibited good antimicrobial activity against E. coli K12. The properties of the obtained material were investigated by the reactions of complete catalytic oxidation of different alkanes and toluene, and it could be suggested that TiO[sub.2]/TeO[sub.2] powders are promising material for use as an active phase in environmental catalysts.