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Low-temperature ultrasound synthesis of nanocrystals CoTiO3 without a calcination step: Effect of ultrasonic waves on formation of the crystal growth mechanism

Moghtada, A ; Sharif University of Technology | 2017

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  1. Type of Document: Article
  2. DOI: 10.1016/j.apt.2016.11.004
  3. Publisher: Elsevier B.V , 2017
  4. Abstract:
  5. CoTiO3 nanocrystallites with an average diameter of 50 nm were synthesized successfully by the sonochemical method without a calcination step and using C10H16N2O8 (EDTA) as the chelating agent. To reach an in-depth understanding of the scientific basis of the proposed process, an in-detail analysis was carried out for characterization of nanoscale CoTiO3 particles via XRD, FTIR, FE-SEM and UV–vis diffuse reflectance spectroscopy (DRS). The crystallite size, average particle size and band gap are found to be 10.7 nm, in the range of 50 nm and 4.64 eV, respectively. The mechanism and the formation process of CoTiO3 in the sonochemical process were proposed. It was found that nanocrystals were formed directly before being oriented and aggregated into large particles in aqueous solution under ultrasonic irradiation. The nucleation in the sonocrystallization process was accelerated by the implosive collapse of bubbles, while the crystal growth process was inhibited or delayed by shock waves and turbulent flow created by ultrasonic radiation. A pure complex perovskite phase of spherical shape was formed completely in a short irradiation time without the calcination process. Sonochemical irradiation could accelerate spherical shape formation of the particles significantly. These results provide new insights into the development and design of better nanomaterial synthesis methods. © 2016 The Society of Powder Technology Japan
  6. Keywords:
  7. Cobalt titanate (CoTiO3;CTO) ; EDTA ; Sonochemical method ; Calcination ; Chelation ; Crystal growth ; Crystallite size ; Energy gap ; Ethylenediaminetetraacetic acid ; Fourier transform infrared spectroscopy ; Irradiation ; Nanocrystals ; Optical properties ; Particle size ; Shock waves ; Solutions ; Sonochemistry ; Ultrasonics ; Cobalt titanate ; Crystal growth mechanism ; Crystal growth process ; In-depth understanding ; Sonochemical irradiation ; Ultrasound irradiation ; UV-Vis diffuse reflectance spectroscopy ; Temperature
  8. Source: Advanced Powder Technology ; Volume 28, Issue 4 , 2017 , Pages 1109-1117 ; 09218831 (ISSN)
  9. URL: https://www.sciencedirect.com/science/article/pii/S092188311630303X