Tin Oxides: Insights into Chemical States from a Nanoparticle Study

Research output: Contribution to journalArticle

Abstract

Tin oxides are semiconductor materials currently attracting close attention in electronics, photovoltaics, gas sensing, and catalysis. Depending on the tin oxidation state - Sn(IV), Sn(II), or intermediate - the corresponding oxide has either n- or p-type natural conductivity, ascribed to oxygen or metal deficiency in the lattice. Such crystalline imperfections severely complicate the task of establishing tin oxidation state, especially at nanoscale. In spite of the striking differences between SnO2 and SnO in their most fundamental properties, there have been enduring problems in identifying the oxide type. These problems were to a great extent caused by the controversy around the characteristic chemical shift, that is, the difference in electron binding energy of a certain core level in an oxide and its parent metal. Using in situ fabricated bare tin oxide nanoparticles, we have been able to resolve the controversy: Our photoelectron spectroscopic study on tin oxide nanoparticles shows that, in contrast to a common opinion of a close chemical shift for SnO2 and SnO, the shift value for tin(IV) oxide is, in fact, 3 times larger than that for tin(II) oxide. Moreover, our investigation of the nanoparticle valence electronic structure clarifies the question of why previously the identification of oxidation states encountered problems.

Details

Authors
Organisations
External organisations
  • Uppsala University
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Chemistry
Original languageEnglish
Pages (from-to)19414-19419
Number of pages6
JournalJournal of Physical Chemistry C
Volume121
Issue number35
StatePublished - 2017 Sep 7
Peer-reviewedYes