In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 118, No. 4 ( 2021-01-26)
Abstract:
Hierarchically ordered oxides are of critical importance in material science and catalysis. Unfortunately, the design and synthesis of such systems remains a key challenge to realizing their potential. In this study, we demonstrate how the deposition of small oligomeric (MoO 3 ) 1–6 clusters—formed by the facile sublimation of MoO 3 powders—leads to the self-assembly of locally ordered arrays of immobilized mono-oxo (MoO 3 ) 1 species on anatase TiO 2 (101). Using both high-resolution imaging and theoretical calculations, we reveal the dynamic behavior of the oligomers as they spontaneously decompose at room temperature, with the TiO 2 surface acting as a template for the growth of this hierarchically structured oxide. Transient mobility of the oligomers on both bare and (MoO 3 ) 1 -covered TiO 2 (101) areas is identified as key to the formation of a complete (MoO 3 ) 1 overlayer with a saturation coverage of one (MoO 3 ) 1 per two undercoordinated surface Ti sites. Simulations reveal a dynamic coupling of the reaction steps to the TiO 2 lattice fluctuations, the absence of which kinetically prevents decomposition. Further experimental and theoretical characterizations demonstrate that (MoO 3 ) 1 within this material are thermally stable up to 500 K and remain chemically identical with a single empty gap state produced within the TiO 2 band structure. Finally, we see that the constituent (MoO 3 ) 1 of this material show no proclivity for step and defect sites, suggesting they can reliably be grown on the (101) facet of TiO 2 nanoparticles without compromising their chemistry.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.2017703118
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
2021
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
