posted on 2019-06-18, 11:35authored byPartha
Pratim Das, P. Sujatha Devi, Douglas A. Blom, Thomas Vogt, Yongjae Lee
Many
aspects of nanostructured materials at high pressures are
still unexplored. We present here, high-pressure structural behavior
of two Zn2SnO4 nanomaterials with inverse spinel
type, one a particle with size of ∼7 nm [zero dimensional (0-D)]
and the other with a chain-like [one dimensional (1-D)] morphology.
We performed in situ micro-Raman and synchrotron X-ray diffraction
measurements and observed that the cation disordering of the 0-D nanoparticle
is preserved up to ∼40 GPa, suppressing the reported martensitic
phase transformation. On the other hand, an irreversible phase transition
is observed from the 1-D nanomaterial into a new and dense high-pressure
orthorhombic CaFe2O4-type structure at ∼40
GPa. The pressure-treated 0-D and 1-D nanomaterials have distinct
diffuse reflectance and emission properties. In particular, a heterojunction
between the inverse spinel and quenchable orthorhombic phases allows
the use of 1-D Zn2SnO4 nanomaterials as efficient
photocatalysts as shown by the degradation of the textile pollutant
methylene blue.