First-principles investigation of optoelectronic and redox properties of (Ta1-xNbx)ON compounds for photocatalysis

Handle URI:
http://hdl.handle.net/10754/564098
Title:
First-principles investigation of optoelectronic and redox properties of (Ta1-xNbx)ON compounds for photocatalysis
Authors:
Harb, Moussab ( 0000-0001-5540-9792 )
Abstract:
We investigate essential fundamental properties of monoclinic (Ta1-xNbx)ON (x = 0.0625, 0.125, 0.25, and 0.5) solid solution semiconductor materials for water splitting using first-principles computations on the basis of density functional theory (DFT) and density functional perturbation theory (DFPT) using the PBE and HSE06 functionals. The formation energies, band gaps, UV-vis optical absorption coefficients, dielectric constants, charge carrier effective masses, and band edge energy positions of these compounds are evaluated. Similarly to TaON, our calculations reveal strongly 3D delocalized characters of the band edge electronic states through the crystal lattices, high dielectric constants, small hole effective masses along the [001] direction, and small electron effective masses along the [100] direction. This leads to good exciton dissociation ability into free charge carriers, good hole mobility along the [001] direction, and good electron mobility along the [100] direction. The main difference, however, is related to their band edge positions with respect to water redox potentials. TaON with a calculated band gap energy of 3.0 eV is predicted as a good candidate for water oxidation and O2 evolution while the (Ta1-xNbx)ON materials (for 0.25 ≤ x ≤ 0.5) with calculated band gap energies between 2.8 and 2.9 eV reveal suitable band edge positions for water oxidation and H+ reduction. These results offer a grand opportunity for these compounds to be properly synthesized and tested for solar-driven overall water-splitting reactions.
KAUST Department:
KAUST Catalysis Center (KCC); Physical Sciences and Engineering (PSE) Division
Publisher:
American Chemical Society (ACS)
Journal:
The Journal of Physical Chemistry C
Issue Date:
5-Mar-2015
DOI:
10.1021/jp511878g
Type:
Article
ISSN:
19327447
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC)

Full metadata record

DC FieldValue Language
dc.contributor.authorHarb, Moussaben
dc.date.accessioned2015-08-03T12:32:04Zen
dc.date.available2015-08-03T12:32:04Zen
dc.date.issued2015-03-05en
dc.identifier.issn19327447en
dc.identifier.doi10.1021/jp511878gen
dc.identifier.urihttp://hdl.handle.net/10754/564098en
dc.description.abstractWe investigate essential fundamental properties of monoclinic (Ta1-xNbx)ON (x = 0.0625, 0.125, 0.25, and 0.5) solid solution semiconductor materials for water splitting using first-principles computations on the basis of density functional theory (DFT) and density functional perturbation theory (DFPT) using the PBE and HSE06 functionals. The formation energies, band gaps, UV-vis optical absorption coefficients, dielectric constants, charge carrier effective masses, and band edge energy positions of these compounds are evaluated. Similarly to TaON, our calculations reveal strongly 3D delocalized characters of the band edge electronic states through the crystal lattices, high dielectric constants, small hole effective masses along the [001] direction, and small electron effective masses along the [100] direction. This leads to good exciton dissociation ability into free charge carriers, good hole mobility along the [001] direction, and good electron mobility along the [100] direction. The main difference, however, is related to their band edge positions with respect to water redox potentials. TaON with a calculated band gap energy of 3.0 eV is predicted as a good candidate for water oxidation and O2 evolution while the (Ta1-xNbx)ON materials (for 0.25 ≤ x ≤ 0.5) with calculated band gap energies between 2.8 and 2.9 eV reveal suitable band edge positions for water oxidation and H+ reduction. These results offer a grand opportunity for these compounds to be properly synthesized and tested for solar-driven overall water-splitting reactions.en
dc.publisherAmerican Chemical Society (ACS)en
dc.titleFirst-principles investigation of optoelectronic and redox properties of (Ta1-xNbx)ON compounds for photocatalysisen
dc.typeArticleen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalThe Journal of Physical Chemistry Cen
kaust.authorHarb, Moussaben
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