Synthesis and Characterizations of Titania-based Composites for Photocatalytic and Opto-Electronics Aapplications /

Abstract

The shortage of clean and freshwater resources is one of main issue for human civilization in 21 century. The wastewater from various industries, laboratories and factories causing toxic efforts on the lives of living organism and impose severe threat to them. The textile industry is one of the biggest consumers of water. The discharge of different toxic dyes and other organic pollutants cause series concerns for living organisms due to carcinogenic effects of these materials. TiO2 being cheap, photo-stable and non-toxic can be use if its photocatalytic activity will increase under solar light. But TiO2 is only active for UV light which account for 4 % of solar spectrum. To enhance its photocatalytic activity under visible spectrum of sunlight, Highly Active TiO2, Er2O3/TiO2, Molybdenum loaded TiO2 and TiO2/Er2O3 photocatalysts were synthesized by Sol-gel method. These synthesized photocatalysts were investigated by applying X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence (PL) emission spectroscopy, UV-vis spectra, and Brunauer–Emmett–Teller (BET). The incorporation of Er2O3 into TiO2 and metal loading of molybdenum into reduced the bandgap of TiO2 from 3.3 eV to 3.25 eV,3.1 eV and 3.09 eV for TiO2-Er2O3, Mo loaded TiO2 and TiO2-Er2O3.BET analysis revealed the enhancement of surface area by adding Er2O3 and Mo which is one of the crucial factor to increase the photocatalytic activity of catalyst. The loading of molybdenum enhanced the immobilization of carriers that facilitated the photooxidation process and suppressed the electron-holes recombination as confirmed by the PL spectroscopy. The photocatalytic activity of these catalysts were evaluated by studying the photodegradation of Methylene blue (MB) under sunlight over standard condition (1 sun,1 atm). The incorporation of Erbium oxide and Impregnation of molybdenum into pure titania and TiO2-Er2O3 increased the degradation efficiency to 37%,58% and 75% respectively. These results supported the effectiveness of titania modified composite for the degradation of industrial textile dye wastewater under sunlight and can be used for opto-electronics applications.