دانلود رایگان مقاله سنتز نانوذرات اکسید اسپینل کبالت با روش پیش پلیمری اصلاح شده

abstract

Metal oxide nanoparticles have been raising increasing interest. In this work, spinel cobalt oxide (Co3O4) nanoparticles of around 29 nm were synthesized using a modified polymeric precursor method. This method is based on the complexation of polyacrylate and cobalt ions in aqueous media by a chelation reaction, resulting in the synthesis of crystalline nanoparticles, confirmed by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Some advantages of this technique are the fast, simple and efficient synthesis of nanoparticles after only 2 h of thermal decomposition at 480
C and elimination of the aging step, which is an essential step in polymeric precursor-based methods such as sol–gel. 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

4. Conclusions

In summary, this work involved the synthesis of nanoparticles. The modified polymeric precursor method proved efficient, yielding pure and highly crystalline spinel-type cobalt oxide with an average particle size of 29 ± 7 nm measured by TEM. The complexation reaction was inferred to be the chelation type, and, because the cobalt coordination number (4 or 6), it is expected the cobalt ions bind to more than one bonding site (carboxylate) of the same molecule (which for a molecular weight of 4500, each chain has approximately 63 carboxylates), forming a stable structure. The total time required to synthesize the nanoparticles was only 6–7 h, with no aging step and a very rapid complexation step of only 10 min at a relatively low temperature of 480
C, attesting to the effectiveness, simplicity and speed of this technique.