No abstract

No abstract

Perovskite zinc titanate (ZnTiO) nanopowders were synthesized using the sonochemical method combined with calcinations at 500 °C and 900 °C for 2 h to improve their crystallinity. The effect of calcination temperature on their structural, optical, and photocatalytic properties has been studied. The cubic phase and the mixing phase of cubic and hexagonal were observed in sample calcined at 600 °C and 700 °C, respectively, while the spinel ZnTiO and rutile TiO phase arises in sample calcined over 700 °C. The valence state was investigated by the X-ray absorption near-edge spectroscopy technique, and the corresponding results indicate the existence of Zn and Ti in the powders. The chemical states of the samples were scrutinized by X-ray photoelectron spectroscopy. The average particle size is approximately 20-240 nm. The excellent photocatalytic performance of ZnTiO nanoparticle calcined at 700 °C gave complete degradation Rhodamine B (RhB) in 75 min under ultraviolet light exposure with the k rate of 0.033 min and 55% of decolorization RhB in 210 min under visible irradiation. The sample calcined at 700 °C ensures a good dielectric permittivity with a value 20 and the loss tangent of about 10 .

No abstract

Metal-doped TiO2 nanoparticles (Metal = Mn, Co, Zn, Ni) were synthesized by sonochemical method accompanying post calcination process using metallic nitrates of manganese, cobalt, zinc, nickel with various metal contents from 0-5 mol% and titanium isopropoxide as a starting precursors. Sodium hydroxide (NaOH) base was used as a precipitating agent. The influence of ultrasound operated at 750 W 20 kHz on the crystalline structure of metal-doped TiO2 nanoparticles has been characterized by X-ray diffraction (XRD) while morphologies and grain size of the nanoparticles were monitored by field emission scanning electron microscope (FE-SEM). The optical absorptivities and corresponding band gaps were evaluated by diffuse reflectance spectroscopy (DRS). The performance of photocatalytic activities of metal-doped TiO2 nanoparticles against aqueous organic dye Rhodamine B (RhB) under visible light was investigated. The results reveal that their crystallinity of synthesized metal doped TiO2 nanoparticles is in mixed phase between anatase, rutile and brookite with calcination temperature at 500 °C for 3 h and their crystalline of all samples are shown. The incorporation of metal dopant on the photocatalytic performance of TiO2 exhibits a significant enhancement in its photocatalytic activities under visible light due to the decrease in band gap energy of metal doped TiO2 nanoparticles.