New insights into the formation of multi-core–shell mesoporous SnO₂@SnS₂ nanostructures

ABSTRACT

SnO₂@SnS₂ multi-core–shell heterostructures were synthesised via chemical conversion of mesoporous raspberry-like SnO₂ nanocrystals. In the syntheses, different concentrations of a sulphide precursor (thioacetamide) were applied. The samples were analysed using scanning and high-resolution transmission electron microscopy, X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The results revealed the presence of surface defects (Sn²⁺, oxygen vacancies) on the raspberry-like surface, which play a crucial role in the chemical conversion reaction. With an increasing amount of thioacetamide, additional redox reactions occurred in the system (Sn⁴⁺/Sn²⁺, S²⁻/S⁰). The highest precursor concentration led to the microstructural disintegration and phase composition change.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

This paper demonstrates the role of defects on the formation of SnO₂@SnS₂ multi-core–shell heterostructures in mesoporous SnO₂ nanomaterials.

KEYWORDS:

• multi-core–shell
• defects
• SnO₂@SnS₂

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work has been financed by The Ministry of Education and Science in Poland, project number DI2018 008148.