Photodegradation of some organic dyes by Nd-doped pyrotitanate nanospongesas visible light catalysts

A۲B۲O۷ mixed metal oxides are interested for their possible applications. A۲B۲O۷compounds are used as photocatalyst for water splitting [۱]. The compounds have an excellentpower for fixing matrices of highly active radionuclides from nuclear wastes [۲]. They are alsoused in electrochemical devices due to their ionic conductivity . Besides, A۲B۲O۷ compounds areknown for their piezo-/ferroelectric properties, used for high temperature devices, and for theirattractive photo-luminescent properties when associated with other lanthanide ions [۳–۴].Nd۲Ti۲O۷ nano-sponges were fabricated via a conventional solid state rout at ۸۰۰ ºC for ۸ hwhen Nd۲O۳ and TiO۲ were used as raw materials. Crystal structural analyses and purity of theobtained materials were analyzed by FullProf program that used profile matching condition withconstant scale factor. Field emission scanning electron microscope (FESEM) was applied tostudy the morphology of the fabricated samples. Ultraviolet – Visible (UV-Vis) spectroscopyshowed that the direct optical band gap energies was ۳.۴۰ for Nd۲Ti۲O۷. The synthesizednanomaterials were used as heterogeneous photocatalysts for the degradation of some waterpollutant organic dyes under direct visible (with fluorescent light with ۴۰ W Power) and UVClights illumination. Malachite green (MG) was used as a typical dye to obtain the optimumphotocatalytic degradation conditions. The photocatalytic performance of the as-fabricatedsamples on the degradation of the pollutant dyes was studied under visible and UVC lightirradiations. The optimum conditions were ۳۵ mg of catalyst, ۰.۰۵ mL of H۲O۲ and ۴۰ minreaction time. The photocatalytic reaction yield was ۹۷% at the present conditions.

کلیدواژه ها:

Ln۲Ti۲O۷ ، heterogeneous photocatalyst ، Degradation ، Malachite Green