Nanocrystalline TiO2 preparation by microwave route and nature of anatase�?�rutile phase transition in nano TiO2

Bulletin of materials science

S A Shivashankar¹  G M Neelgund¹  K J Rao²  B K Chethana²  P P Sahoo² 

[1] Materials Research Centre, Indian Institute of Science, Bangalore 560 012, India$$Materials Research Centre, Indian Institute of Science, Bangalore 560 012, IndiaMaterials Research Centre, Indian Institute of Science, Bangalore 560 012, India$$;Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India$$Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, IndiaSolid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India$$

关键词: TiO2;    microwave irradiation;    anatase;    rutile;    metalorganic synthesis;    PVP.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Nanopowders of TiO₂ has been prepared using a microwave irradiation-assisted route, starting from a metalorganic precursor, bis(ethyl-3-oxo-butanoato)oxotitanium (IV), [TiO(etob)₂]₂. Polyvinylpyrrolidone (PVP) was used as a capping agent. The as-prepared amorphous powders crystallize into anatase phase, when calcined. At higher calcination temperature, the rutile phase is observed to form in increasing quantities as the calcination temperature is raised. The structural and physicochemical properties were measured using XRD, FTâ€�?�IR, SEM, TEM and thermal analyses. The mechanisms of formation of nano-TiO₂ from the metalâ€�?�organic precursor and the irreversible phase transformation of nano TiO₂ from anatase to rutile structure at higher temperatures have been discussed. It is suggested that a unique step of initiation of transformation takes place in Ti_1/2O layers in anatase which propagates. This mechanism rationalizes several key observations associated with the anataseâ€�?�rutile transformation.

【 授权许可】

Unknown