Phase Transformation and Morphology Evolution Characteristics of Hydrothermally Prepared Boehmite Particles
Under hydrothermal condition, benefiting from dehydration and in situ nucleation processes, well-crystallized 3-dimensional (3D) boehmite nanoparticles with an average diameter of around 400 nm was directly converted from gibbsite phase in aluminum oxyhydroxide powder without adding any kinds of other assistants. Through investigation the influences of different factors, it is concluded that, hydrothermal treating temperature, time and initial slurry pH play an important role in obtaining well-crystallized boehmite particles. Besides XRD and FE-SEM, TG/DTA, FT-IR and Raman spectra were also employed to follow and confirm the formation of boehmite, which is useful for optimizing the synthesis condition. Moreover, after the hydrothermal treatment under the optimum condition, because as-prepared 3D boehmite nanoparticles have abundant surface oxygen anionic vacancies (F and F+-centers), thus endowing it optical band gap around 5.41 eV. This technique is significant and useful for developing a new opportunity for large scale production of well-crystallized boehmite powder with high purity from aluminum oxyhydroxide powder.
KeywordsHydrothermal treating Boehmite Gibbsite Surface defects Phase transformation Optical properties
This study was partially financially supported by the National Natural Science Foundation of China (24101210), Qinghai Science &Technology Projects (2016-GX-102), Youth Innovation Promotion Association CAS (2016376), CAS “light of West China” program, Hundred-Talent Program (Chinese academy of Sciences) and open project of State Key Laboratory of Chemical Resource Engineering (CRE-2017-c-202).
Compliance with Ethical Standards
Conflict of interest
There are no conflicts of interest which might bias or otherwise influence this work by the authors.