Ultrasonic spray pyrolysis of surface modified TiO₂ nanoparticles with聽dopamine

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• 作者：Ivan M. Dug ; 啪i膰 ; Dragana J. Jovanovi膰 ; Lidija T. Man膷i膰 ; Olivera B. Milo拧evi膰 ; Scott P. Ahrenkiel ; Zoran V. 艩aponji膰 ; Jovan M. Nedeljkovi膰
• 关键词：Surfaces ; Electron microscopy (STEM ; TEM and SEM) ; Fourier transform infrared spectroscopy (FTIR) ; Ultrasonic techniques ; Optical properties
• 刊名：Materials Chemistry and Physics
• 出版年：16 December, 2013
• 年：2013
• 卷：143
• 期：1
• 页码：233-239
• 全文大小：1925 K

文摘

Spherical, submicronic TiO₂ powder particles were prepared in the low temperature process of ultrasonic spray pyrolysis (150聽掳C) by using as a precursor aqueous colloidal solutions consisting of surface modified 45聽脜 TiO₂ nanoparticles with dopamine. Detailed structural and morphological characterization of colored submicronic TiO₂ spheres was performed by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), laser particle size analysis and FTIR techniques. Also, optical characterization of both dopamine-modified TiO₂ precursor nanoparticles and submicronic TiO₂ powder particles was performed using absorption and diffuse reflectance spectroscopy, respectively. A significant decrease of the effective band gap (1.9聽eV) in dopamine-modified TiO₂ nanoparticles compared to the band gap of bulk material (3.2聽eV) was preserved after formation of submicronic TiO₂ powder particles in the process of ultrasonic spray pyrolysis under mild experimental conditions. Due to the nanostructured nature, surface-modified assemblage of TiO₂ nanoparticles preserved unique ability to absorb light through charge transfer complex by photoexcitation of the ligand-to-TiO₂ band, conventionally associated with extremely small TiO₂ nanoparticles (d聽<聽20聽nm) whose surface Ti atoms, owing to the large curvature, have penta-coordinate geometry.