1D Narrow-Bandgap Tin Oxide Materials: Systematic High-Resolution TEM and Raman Analysis

Kazuhiro Manseki; Saeid Vafaei; Loren Scott; Katelyn Hampton; Nagisa Hattori; Kosuke Ohira; Kyle Prochotsky; Stephen Jala; Takashi Sugiura

doi:10.3390/ma16134539

1D Narrow-Bandgap Tin Oxide Materials: Systematic High-Resolution TEM and Raman Analysis

Materials (Basel). 2023 Jun 23;16(13):4539. doi: 10.3390/ma16134539.

Authors

Kazuhiro Manseki¹, Saeid Vafaei², Loren Scott², Katelyn Hampton², Nagisa Hattori¹, Kosuke Ohira¹, Kyle Prochotsky², Stephen Jala³, Takashi Sugiura¹

Affiliations

¹ Graduate School of Natural Science and Technology, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
² Mechanical Engineering Department, Bradley University, 1501 West Bradley Avenue, Peoria, IL 61625, USA.
³ Industrial and Manufacturing Engineering and Technology Department, Bradley University, Peoria, IL 61625, USA.

Abstract

We demonstrate for the first time the structure identification and narrow-bandgap property of 1D hybridized SnO/SnO₂ nanoparticles derived from the calcination of a single-source precursor, i.e., tin(II) oxalate. Systematic Raman analysis together with high-resolution TEM (HR-TEM) measurements of the tin oxide samples were carried out by changing the calcination temperatures. These data revealed the simultaneous formation of 1D SnO/SnO₂ in the rod particles that grew in air. It was also found that Sn(II) can be introduced by changing the concentration of Sn(II) salt in the precursor synthesis and the maximum temperature in calcination. Particles measuring 20~30 nm were sintered to produce tin oxide nanorods including tin monoxide, SnO. Photoabsorption properties associated with the formation of the SnO/SnO₂ nanocomposites were also investigated. Tauc plots indicate that the obtained tin oxide samples had a lower bandgap of 2.9~3.0 eV originating from SnO in addition to a higher bandgap of around 3.5~3.7 eV commonly observed for SnO₂. Such 1D SnO_x/SnO₂ hybrids via tin oxalate synthesis with this optical property would benefit new materials design for photoenergy conversion systems, such as photocatalysts.

Keywords: Raman; TEM; bandgap; calcination; tin oxide.

Grants and funding

This work was supported by the Illinois Space Grant Consortium, USA and the Research Excellence Program at and a Caterpillar Fellowship from Bradley University, USA. This work was also partially supported by the Koshiyama Science & Technology Foundation and CCI holdings Co., Ltd., Japan.