On the relationship between rutile/anatase ratio and the nature of defect states in sub-100 nm TiO2 nanostructures: experimental insights

Handle URI:
http://hdl.handle.net/10754/627267
Title:
On the relationship between rutile/anatase ratio and the nature of defect states in sub-100 nm TiO2 nanostructures: experimental insights
Authors:
Soliman, Moamen M.; Al Haron, Mohamed H.; Samir, Menna; Tolba, Sarah A.; Shaheen, Basamat; Amer, Ahmed W.; Mohammed, Omar F. ( 0000-0001-8500-1130 ) ; Allam, Nageh K. ( 0000-0001-9458-3507 )
Abstract:
Black TiO2 is being widely investigated due to its superior optical activity and potential applications in photocatalytic hydrogen generation. Herein, the limitations of the hydrogenation process of TiO2 nanostructures are unraveled by exploiting the fundamental tradeoffs affecting the overall efficiency of the water splitting process. To control the nature and concentration of defect states, different reduction rates are applied to sub-100 nm TiO2 nanotubes, chosen primarily for their superiority over their long counterparts. X-Ray Photoelectron Spectroscopy disclosed changes in the stoichiometry of TiO2 with the reduction rate. UV-vis and Raman spectra showed that high reduction rates promote the formation of the rutile phase in TiO2, which is inactive towards water splitting. Furthermore, electrochemical analysis revealed that such high rates induce a higher concentration of localized electronic defect states that hinder the water splitting performance. Finally, incident photon-to-current conversion efficiency (IPCE) highlighted the optimum reduction rate that attains a relatively lower defect concentration as well as lower rutile content, thereby achieving the highest conversion efficiency.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Solar Center (KSC)
Citation:
Soliman MM, Al Haron MH, Samir M, Tolba SA, Shaheen BS, et al. (2018) On the relationship between rutile/anatase ratio and the nature of defect states in sub-100 nm TiO2 nanostructures: experimental insights. Physical Chemistry Chemical Physics 20: 5975–5982. Available: http://dx.doi.org/10.1039/c7cp08629f.
Publisher:
Royal Society of Chemistry (RSC)
Journal:
Physical Chemistry Chemical Physics
Issue Date:
2-Feb-2018
DOI:
10.1039/c7cp08629f
Type:
Article
ISSN:
1463-9076; 1463-9084
Additional Links:
http://pubs.rsc.org/en/Content/ArticleLanding/2018/CP/C7CP08629F#!divAbstract
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; KAUST Solar Center (KSC)

Full metadata record

DC FieldValue Language
dc.contributor.authorSoliman, Moamen M.en
dc.contributor.authorAl Haron, Mohamed H.en
dc.contributor.authorSamir, Mennaen
dc.contributor.authorTolba, Sarah A.en
dc.contributor.authorShaheen, Basamaten
dc.contributor.authorAmer, Ahmed W.en
dc.contributor.authorMohammed, Omar F.en
dc.contributor.authorAllam, Nageh K.en
dc.date.accessioned2018-03-11T06:54:13Z-
dc.date.available2018-03-11T06:54:13Z-
dc.date.issued2018-02-02en
dc.identifier.citationSoliman MM, Al Haron MH, Samir M, Tolba SA, Shaheen BS, et al. (2018) On the relationship between rutile/anatase ratio and the nature of defect states in sub-100 nm TiO2 nanostructures: experimental insights. Physical Chemistry Chemical Physics 20: 5975–5982. Available: http://dx.doi.org/10.1039/c7cp08629f.en
dc.identifier.issn1463-9076en
dc.identifier.issn1463-9084en
dc.identifier.doi10.1039/c7cp08629fen
dc.identifier.urihttp://hdl.handle.net/10754/627267-
dc.description.abstractBlack TiO2 is being widely investigated due to its superior optical activity and potential applications in photocatalytic hydrogen generation. Herein, the limitations of the hydrogenation process of TiO2 nanostructures are unraveled by exploiting the fundamental tradeoffs affecting the overall efficiency of the water splitting process. To control the nature and concentration of defect states, different reduction rates are applied to sub-100 nm TiO2 nanotubes, chosen primarily for their superiority over their long counterparts. X-Ray Photoelectron Spectroscopy disclosed changes in the stoichiometry of TiO2 with the reduction rate. UV-vis and Raman spectra showed that high reduction rates promote the formation of the rutile phase in TiO2, which is inactive towards water splitting. Furthermore, electrochemical analysis revealed that such high rates induce a higher concentration of localized electronic defect states that hinder the water splitting performance. Finally, incident photon-to-current conversion efficiency (IPCE) highlighted the optimum reduction rate that attains a relatively lower defect concentration as well as lower rutile content, thereby achieving the highest conversion efficiency.en
dc.publisherRoyal Society of Chemistry (RSC)en
dc.relation.urlhttp://pubs.rsc.org/en/Content/ArticleLanding/2018/CP/C7CP08629F#!divAbstracten
dc.titleOn the relationship between rutile/anatase ratio and the nature of defect states in sub-100 nm TiO2 nanostructures: experimental insightsen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentKAUST Solar Center (KSC)en
dc.identifier.journalPhysical Chemistry Chemical Physicsen
dc.contributor.institutionEnergy Materials Laboratory, School of Sciences and Engineering, The American University in Cairo, New Cairo 11835, Egypt.en
kaust.authorShaheen, Basamaten
kaust.authorMohammed, Omar F.en
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