文献类型：期刊文献

英文题名：Insight into the crystal lattice formation of brookite in aqueous ammonia media: the electrolyte effect

作者：Jiao, Yanchao;Zhao, Bin;Chen, Feng[1];Zhang, Jinlong

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China; E China Univ Sci & Technol, Inst Fine Chem, Shanghai 200237, Peoples R China

年份：2011

卷号：13

期号：12

起止页码：4167

外文期刊名：CRYSTENGCOMM

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000291218500033)】；

基金：This work was supported by the National Nature Science Foundation of China (20777015) and the Fundamental Research Funds for the Central Universities.

语种：英文

摘要：A feasible approach to synthesize pure brookite was achieved in an aqueous ammonia system via a hydrothermal process. By hydrothermal treatment of the titanate that directly hydrolyzed from tetrabutyl titanate (TBOT), a phase transition from titanate to TiO(2) was observed with XRD. Anatase TiO(2) was produced with an unobstructed closure of titanate layers. The phase transition process can be controlled by adding an electrolyte such as NaCl into the hydrothermal media. Na(+) ions locally stop the direct closure of titanate layers at their adjacent position, which induce the formation of a brookite-like structure. The optimal hydrothermal reaction parameters for the crystal lattice formation of brookite in aqueous ammonia media were found to be 180 degrees C, 0.5 M NaCl and >= 72 h. The phase transition process of titanate precursor to TiO(2) depends heavily on the electrolyte. Metal cations play a crucial role in conducting the transition procedure from layered titanate into brookite or anatase. Na(+) is preferred to conduct the phase transition from titanate to brookite rather than K(+) and Li(+). Although anions do not determine the phase transition rule during the hydrothermal process, they are influential in the phase transition process, as they can promote the phase transition by interacting with the TiO(6) octahedra.