Electronic structure and photocatalytic activity of wurtzite Cu–Ga–S nanocrystals and their Zn substitution

Handle URI:
http://hdl.handle.net/10754/347343
Title:
Electronic structure and photocatalytic activity of wurtzite Cu–Ga–S nanocrystals and their Zn substitution
Authors:
Kandiel, Tarek; Anjum, Dalaver H.; Sautet, Philippe; Le Bahers, Tangui; Takanabe, Kazuhiro ( 0000-0001-5374-9451 )
Abstract:
Stoichiometric and gallium-rich wurtzite Cu-Ga-S ternary nanocrystals were synthesized via a facile solution-based hot injection method using 1-dodecanethiol as a sulfur source. The use of 1-dodecanethiol was found to be essential not only as a sulfur source but also as a structure-directing reagent to form a metastable wurtzite structure. In addition, the substitution of zinc in the wurtzite gallium-rich Cu-Ga-S nanocrystals was also investigated. The obtained nanocrystals were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and inductively coupled plasma atomic emission spectroscopy (ICP-OES). Electronic structures of pristine and the Zn-substituted Cu-Ga-S system were investigated using density functional theory (DFT) with HSE06 exchange-correlation functional. The calculated bandgaps accurately reflect the measured ones. The allowed electronic transitions occur upon the photon absorption from the (Cu + S) band towards the (Ga + S) one. The Zn substitution was found not to contribute to the band edge structure and hence altered the bandgaps only slightly, the direct transition nature remaining unchanged with the Zn substitution. The photocatalytic activities of H2 evolution from an aqueous Na2S/Na2SO3 solution under visible-light illumination on the synthesized nanocrystals were investigated. While the stoichiometric CuGaS2 exhibited negligible activity, the gallium-rich Cu-Ga-S ternary nanocrystals displayed reasonable activity. The optimum Zn substitution in the gallium-rich Cu-Ga-S ternary nanocrystals enhanced the H2 evolution rate, achieving an apparent quantum efficiency of >6% at 400 nm. © 2015 The Royal Society of Chemistry.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC); Advanced Nanofabrication, Imaging and Characterization Core Lab
Citation:
Electronic structure and photocatalytic activity of wurtzite Cu–Ga–S nanocrystals and their Zn substitution 2015 J. Mater. Chem. A
Publisher:
Royal Society of Chemistry (RSC)
Journal:
J. Mater. Chem. A
Issue Date:
23-Mar-2015
DOI:
10.1039/C5TA01552A
Type:
Article
ISSN:
2050-7488; 2050-7496
Additional Links:
http://xlink.rsc.org/?DOI=C5TA01552A
Appears in Collections:
Articles; Advanced Nanofabrication, Imaging and Characterization Core Lab; Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC)

Full metadata record

DC FieldValue Language
dc.contributor.authorKandiel, Tareken
dc.contributor.authorAnjum, Dalaver H.en
dc.contributor.authorSautet, Philippeen
dc.contributor.authorLe Bahers, Tanguien
dc.contributor.authorTakanabe, Kazuhiroen
dc.date.accessioned2015-03-31T06:41:48Zen
dc.date.available2015-03-31T06:41:48Zen
dc.date.issued2015-03-23en
dc.identifier.citationElectronic structure and photocatalytic activity of wurtzite Cu–Ga–S nanocrystals and their Zn substitution 2015 J. Mater. Chem. Aen
dc.identifier.issn2050-7488en
dc.identifier.issn2050-7496en
dc.identifier.doi10.1039/C5TA01552Aen
dc.identifier.urihttp://hdl.handle.net/10754/347343en
dc.description.abstractStoichiometric and gallium-rich wurtzite Cu-Ga-S ternary nanocrystals were synthesized via a facile solution-based hot injection method using 1-dodecanethiol as a sulfur source. The use of 1-dodecanethiol was found to be essential not only as a sulfur source but also as a structure-directing reagent to form a metastable wurtzite structure. In addition, the substitution of zinc in the wurtzite gallium-rich Cu-Ga-S nanocrystals was also investigated. The obtained nanocrystals were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and inductively coupled plasma atomic emission spectroscopy (ICP-OES). Electronic structures of pristine and the Zn-substituted Cu-Ga-S system were investigated using density functional theory (DFT) with HSE06 exchange-correlation functional. The calculated bandgaps accurately reflect the measured ones. The allowed electronic transitions occur upon the photon absorption from the (Cu + S) band towards the (Ga + S) one. The Zn substitution was found not to contribute to the band edge structure and hence altered the bandgaps only slightly, the direct transition nature remaining unchanged with the Zn substitution. The photocatalytic activities of H2 evolution from an aqueous Na2S/Na2SO3 solution under visible-light illumination on the synthesized nanocrystals were investigated. While the stoichiometric CuGaS2 exhibited negligible activity, the gallium-rich Cu-Ga-S ternary nanocrystals displayed reasonable activity. The optimum Zn substitution in the gallium-rich Cu-Ga-S ternary nanocrystals enhanced the H2 evolution rate, achieving an apparent quantum efficiency of >6% at 400 nm. © 2015 The Royal Society of Chemistry.en
dc.publisherRoyal Society of Chemistry (RSC)en
dc.relation.urlhttp://xlink.rsc.org/?DOI=C5TA01552Aen
dc.rightsArchived with thanks to J. Mater. Chem. Aen
dc.titleElectronic structure and photocatalytic activity of wurtzite Cu–Ga–S nanocrystals and their Zn substitutionen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentAdvanced Nanofabrication, Imaging and Characterization Core Laben
dc.identifier.journalJ. Mater. Chem. Aen
dc.eprint.versionPost-printen
dc.contributor.institutionDepartment of Chemistry, Faculty of Science, Sohag University, Sohag 82524, Egypt.en
dc.contributor.institutionUniversité de Lyon, Université Claude Bernard Lyon1, ENS Lyon, Centre National de Recherche Scientifique, 46 allée d’Italie, 69007 Lyon Cedex 07, France.en
dc.contributor.affiliationKing Abdullah University of Science and Technology (KAUST)en
kaust.authorTakanabe, Kazuhiroen
kaust.authorKandiel, Tareken
kaust.authorAnjum, Dalaver H.en

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