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Electrochemically self-doped hierarchical TiO2 nanotube arrays for enhanced visible-light photoelectrochemical performance: an experimental and computational study

TitleElectrochemically self-doped hierarchical TiO2 nanotube arrays for enhanced visible-light photoelectrochemical performance: an experimental and computational study
Publication TypeJournal Article
Year of Publication2016
AuthorsYang, Y, Liao, JJ, Li, YF, Cao, XK, Li, N, Wang, CZ, Lin, SW
JournalRCS Advances
Volume6
Pagination46871-46878
Date Published05
Type of ArticleArticle
ISBN Number2046-2069
Accession NumberWOS:000377254800090
Keywords001 facets, activity, chemistry, fabrication, films, oxygen vacancy, photo-assisted deposition, photoanodes, photocatalytic, ti3+, titanium, water-splitting performance
Abstract

A two-step electrochemical anodization method was used to prepare typical hierarchical top-ring/bottomtube TiO2 nanotube arrays (TNTAs). Ti3+ self-doping into TiO2 was achieved via electrochemical reduction at different negative potentials in the range from -1.0 V to -1.6 V. Compared with the pristine TNTAs, the TNTAs reduced at -1.4 V presented a dramatically enhanced photoelectrochemical performance, which showed a 2.4 times enhancement in photocurrent density under simulated AM 1.5G illumination and 2.3 times increase in visible-light photocurrent density. Approximately 100% improvement in photoelectrochemical catalytic efficiency was obtained in a phenol degradation experiment. First-principles calculations demonstrated that the new states induced by Ti3+ self-doping might act as a shallow donor level to promote the separation of photogenerated electron-hole pairs. Moreover, the light absorption improved by the hierarchical nanostructure and the excellent electron conductivity induced by Ti3+ doping also account for the enhancement in the photoelectrochemical performance. These results suggest a reasonable design of photoelectrodes for efficient photoelectrochemical applications in the future.

DOI10.1039/c6ra05805a
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Exploratory Theory

Short TitleRSC Adv.
Alternate JournalRSC Adv.