Termination Effects in Aluminosilicate and Aluminogermanate Imogolite Nanotubes: A Density Functional Theory Study

Poli, Emiliano, Elliott, Joshua D, Chai, Ziwei and Teobaldi, Gilberto ORCID: 0000-0001-6068-6786 (2020) Termination Effects in Aluminosilicate and Aluminogermanate Imogolite Nanotubes: A Density Functional Theory Study. CRYSTALS, 10 (11). p. 1051.

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Official URL: http://dx.doi.org/10.3390/cryst10111051

Abstract

<jats:p>We investigate termination effects in aluminosilicate (AlSi) and aluminogermanate (AlGe) imogolite nanotubes (NTs) by means of semi-local and range-corrected hybrid Density Functional Theory (DFT) simulations. Following screening and identification of the smallest finite model capable of accommodating full relaxation of the NT terminations around an otherwise geometrically and electrostatically unperturbed core region, we quantify and discuss the effects of physical truncation on the structure, relative energy, electrostatics and electronic properties of differently terminated, finite-size models of the NTs. In addition to composition-dependent changes in the valence (VB) and conduction band (CB) edges and resultant band gap (BG), the DFT simulations uncover longitudinal band bending and separation in the finite AlSi and AlGe models. Depending on the given termination of the NTs, such longitudinal effects manifest in conjunction with the radial band separation typical of fully periodic AlSi and AlGe NTs. The strong composition dependence of the longitudinal and radial band bending in AlSi and AlGe NTs suggests different mechanisms for the generation, relaxation and separation of photo-generated holes in AlSi and AlGe NTs, inviting further research in the untapped potential of imogolite compositional and structural flexibility for photo-catalytic applications.</jats:p>

Item Type:	Article
Uncontrolled Keywords:	inorganic nanotubes, imogolite nanotubes, DFT, surface terminations
Depositing User:	Symplectic Admin
Date Deposited:	25 Nov 2020 11:15
Last Modified:	18 Jan 2023 23:20
DOI:	10.3390/cryst10111051
Open Access URL:	https://www.mdpi.com/2073-4352/10/11/1051/htm
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3108105