温度对TiO_2-B纳米纤维的结晶度和稳定性的影响

Influence of Temperature on the Crystallinity and Stability of TiO_2-B Nanofibers

本文以锐钛矿相二氧化钛纳米颗粒和NaOH溶液为前驱物,通过水热反应和退火处理制备了TiO2-B纳米纤维。用XRD、HRTEM和EDS对样品的结构、形貌及其演化进行了表征。讨论了水热反应温度和退火温度对TiO2-B纳米纤维的结晶度、形貌和热稳定性的影响。结果表明:在160℃、180℃和200℃温度下水热反应,分别得到H2Ti4O9、H2Ti3O7和H2Ti4O9与H2Ti3O7混合的纳米纤维,400℃退火后,无论是H2Ti4O9还是H2Ti3O7纳米纤维都转化为TiO2-B纳米纤维,但从180℃水热反应得到的H2Ti3O7纳米纤维转化的TiO2-B纳米纤维具有较高结晶度和热稳定性。

TiO2-B nanofibers were prepared by the hydrothermal reaction of anatase nanoparticles with NaOH aqueous solution and a heat treatment.The structure,morphology and evolution of the nanofibers were characterized by XRD,HRTEM and EDS.The influences of hydrothermal reaction temperature and annealing temperature on the morphology,crystallinity,thermal stability and crystal structure of TiO2-B nanofibers were discussed in detail.The results show that H2Ti4O9,H2Ti3O7 nanofibers and mixture of H2Ti4O9 and H2Ti3O7 nanofibers were obtained at hydrothermal reaction temperatures of 160,180 and 200 ℃,respectively.Both H2Ti4O9 and H2Ti3O7 nanofibers transformed to TiO2-B nanofibers after 400 ℃ annealing for 4 h.The TiO2-B nanofibers transformed from H2Ti3O7 nanofibers obtained in hydrothermal reaction at 180 ℃ had high crystallinity and thermal stability.