Electrochemical reduction induced self-doping of Ti3+ for efficient water splitting performance on TiO2 based photoelectrodes

Handle URI:
http://hdl.handle.net/10754/562526
Title:
Electrochemical reduction induced self-doping of Ti3+ for efficient water splitting performance on TiO2 based photoelectrodes
Authors:
Zhang, Zhonghai; Hedhili, Mohamed N. ( 0000-0002-3624-036X ) ; Zhu, Haibo; Wang, Peng ( 0000-0003-0856-0865 )
Abstract:
Hetero-element doping (e.g., N, F, C) of TiO2 is inevitably accompanied by significantly increased structural defects due to the dopants' nature being foreign impurities. Very recently, in situ self-doping with homo-species (e.g., Ti3+) has been emerging as a rational solution to enhance TiO2 photoactivity within both UV and visible light regions. Herein we demonstrate that conventional electrochemical reduction is indeed a facile and effective strategy to induce in situ self-doping of Ti3+ into TiO2 and the self-doped TiO2 photoelectrodes showed remarkably improved and very stable water splitting performance. In this study, hierarchical TiO2 nanotube arrays (TiO2 NTs) were chosen as TiO2 substrates and then electrochemically reduced under varying conditions to produce Ti3+ self-doped TiO2 NTs (ECR-TiO2 NTs). The optimized saturation photocurrent density and photoconversion efficiency on the ECR-TiO2 NTs under simulated AM 1.5G illumination were identified to be 2.8 mA cm-2 at 1.23 V vs. RHE and 1.27% respectively, which are the highest values ever reported for TiO 2 based photoelectrodes. The electrochemical impedance spectra measurement confirms that the electrochemical induced Ti3+ self-doping improved the electrical conductivity of the ECR-TiO2 NTs. The versatility and effectiveness of the electrochemical reduction method for Ti3+ self-doping in P25 based TiO2 was also examined and confirmed. This journal is © 2013 the Owner Societies.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; Environmental Science and Engineering Program; Water Desalination and Reuse Research Center (WDRC); Advanced Nanofabrication, Imaging and Characterization Core Lab; KAUST Catalysis Center (KCC); Physical Sciences and Engineering (PSE) Division; Water Desalination & Reuse Research Cntr; Core Labs; Environmental Nanotechnology Lab
Publisher:
Royal Society of Chemistry
Journal:
Physical Chemistry Chemical Physics
Issue Date:
2013
DOI:
10.1039/c3cp52759j
Type:
Article
ISSN:
14639076
Sponsors:
This work was supported by the KAUST baseline fund.
Appears in Collections:
Articles; Environmental Science and Engineering Program; Advanced Nanofabrication, Imaging and Characterization Core Lab; Physical Sciences and Engineering (PSE) Division; KAUST Catalysis Center (KCC); Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorZhang, Zhonghaien
dc.contributor.authorHedhili, Mohamed N.en
dc.contributor.authorZhu, Haiboen
dc.contributor.authorWang, Pengen
dc.date.accessioned2015-08-03T10:41:24Zen
dc.date.available2015-08-03T10:41:24Zen
dc.date.issued2013en
dc.identifier.issn14639076en
dc.identifier.doi10.1039/c3cp52759jen
dc.identifier.urihttp://hdl.handle.net/10754/562526en
dc.description.abstractHetero-element doping (e.g., N, F, C) of TiO2 is inevitably accompanied by significantly increased structural defects due to the dopants' nature being foreign impurities. Very recently, in situ self-doping with homo-species (e.g., Ti3+) has been emerging as a rational solution to enhance TiO2 photoactivity within both UV and visible light regions. Herein we demonstrate that conventional electrochemical reduction is indeed a facile and effective strategy to induce in situ self-doping of Ti3+ into TiO2 and the self-doped TiO2 photoelectrodes showed remarkably improved and very stable water splitting performance. In this study, hierarchical TiO2 nanotube arrays (TiO2 NTs) were chosen as TiO2 substrates and then electrochemically reduced under varying conditions to produce Ti3+ self-doped TiO2 NTs (ECR-TiO2 NTs). The optimized saturation photocurrent density and photoconversion efficiency on the ECR-TiO2 NTs under simulated AM 1.5G illumination were identified to be 2.8 mA cm-2 at 1.23 V vs. RHE and 1.27% respectively, which are the highest values ever reported for TiO 2 based photoelectrodes. The electrochemical impedance spectra measurement confirms that the electrochemical induced Ti3+ self-doping improved the electrical conductivity of the ECR-TiO2 NTs. The versatility and effectiveness of the electrochemical reduction method for Ti3+ self-doping in P25 based TiO2 was also examined and confirmed. This journal is © 2013 the Owner Societies.en
dc.description.sponsorshipThis work was supported by the KAUST baseline fund.en
dc.publisherRoyal Society of Chemistryen
dc.titleElectrochemical reduction induced self-doping of Ti3+ for efficient water splitting performance on TiO2 based photoelectrodesen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentEnvironmental Science and Engineering Programen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.contributor.departmentAdvanced Nanofabrication, Imaging and Characterization Core Laben
dc.contributor.departmentKAUST Catalysis Center (KCC)en
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentWater Desalination & Reuse Research Cntren
dc.contributor.departmentCore Labsen
dc.contributor.departmentEnvironmental Nanotechnology Laben
dc.identifier.journalPhysical Chemistry Chemical Physicsen
kaust.authorZhang, Zhonghaien
kaust.authorHedhili, Mohamed N.en
kaust.authorZhu, Haiboen
kaust.authorWang, Pengen
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