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Crystal properties without crystallinity? Influence of surface hydroxylation on the structure and properties of small TiO2 nanoparticles
被引:7
作者:
Recio-Poo, Miguel
[1
,2
]
Morales-Garcia, Angel
[1
,2
]
Illas, Francesc
[1
,2
]
Bromley, Stefan T. T.
[1
,2
,3
]
机构:
[1] Univ Barcelona, Dept Ciencia Mat Quim Fis i, c Marti i Franques 1-11, Barcelona 08028, Spain
[2] Univ Barcelona, Inst Quim Teor Computac IQTCUB i, c Marti i Franques 1-11, Barcelona 08028, Spain
[3] Institucio Catalana Recerca & Estudis Avancats ICR, Passeig Lluis Co 23, Barcelona 08010, Spain
来源:
关键词:
PHASE-STABILITY;
ANATASE;
WATER;
DENSITY;
RUTILE;
PHOTOCATALYSIS;
TRANSFORMATION;
NANOMATERIALS;
NANOCLUSTERS;
OPTIMIZATION;
D O I:
10.1039/d3nr00141e
中图分类号:
O6 [化学];
学科分类号:
0703 ;
摘要:
Titania (TiO2) nanoparticles (NPs) are widely employed in applications that take advantage of their photochemical properties (e.g. pollutant degradation, photocatalysis). Here, we study the interrelation between crystallinity, surface hydroxylation and electronic structure in titania NPs with 1.4-2.3 nm diameters using all electron density functional theory-based calculations. We show how the distribution of local coordination environments of the atoms in thermally annealed quasi-spherical non-crystalline NPs converge to those in correspondingly sized faceted crystalline anatase NPs upon increasing hydroxylation. When highly hydroxylated, annealed NPs also possess electronic energy gaps with very similar energies and band edge orbital characters to those of the crystalline anatase NPs. We refer to the crystallite-mimicking non-crystalline annealed NPs as "crystalikes". Small stable crystalike NPs could allow for photochemical applications of titania in the size range where crystalline anatase NPs tend to become thermodynamically unfavoured (<3-5 nm). Our work implies the anatase crystal structure may not be as essential as previously assumed for TiO2 NP applications and generally suggests that crystalikes could be possible in other nanomaterials.
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页码:4809 / 4820
页数:12
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