The potential of Imogolite nanotubes as (co-)photocatalyst: a linear-scaling Density Functional Theory study

(2015) The potential of Imogolite nanotubes as (co-)photocatalyst: a linear-scaling Density Functional Theory study. Journal of Physics: Condensed Matter. (Submitted)

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Abstract

We report a linear-scaling Density Functional Theory (DFT) study of the structure, wall-polarization absolute band-alignment and optical absorption of several, recently synthesized, open-ended Imogolite (Imo) nanotubes (NTs), namely single-walled (SW) aluminosilicate (AlSi), SW aluminogermanate (AlGe) , SW methylated aluminosilicate (AlSi-Me), and double-walled (DW) AlGe NTs. Simulations with three different semi-local and dispersion-corrected DFT-functionals reveal that the NT wall-polarization can be increased by nearly a factor of four going from SW-AlSi-Me to DW-AlGe. Absolute vacuum alignment of the NT electronic bands and comparison with those of rutile and anatase TiO2 suggest that the NTs may exhibit marked propensity to both photo-reduction and hole-scavenging. Characterization of the NTs’ bandseparation and optical properties reveal the occurrence of (near-)UV inside-outside charge-transfer excitations, which may be effective for electron-hole separation and enhanced photocatalytic activity. Finally, the effects of the NTs’ wall-polarization on the absolute alignment of electron and hole acceptor states of interacting water (H2O) molecules are quantified and discussed.

Item Type:	Article
Subjects:	Q Science > QC Physics Q Science > QD Chemistry
Depositing User:	Symplectic Admin
Date Deposited:	04 Aug 2015 09:52
Last Modified:	31 Mar 2016 12:39
URI:	http://livrepository.liverpool.ac.uk/id/eprint/2018726

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