Abstract
Two types of core-shell heterostructure TiO2 nanofibers (noted as core@shell TiO2 NFs) were synthesized by sequential hydrothermal, calcination, and impregnation processes. Rutile TiO2 nanofibers (R TiO2 NFs) core with anatase TiO2 nanoparticles (A TiO2 NPs) shell is denoted as R@A TiO2 NFs, and the reverse structure with anatase TiO2 NFs core (A TiO2 NFs) and rutile TiO2 nanoparticles shell (R TiO2 NPs) is denoted as A@R TiO2 NFs. In our study, the photodegradation of organic dyes and Kelvin probe force microscopy (KPFM) analysis were applied to shed light on the mechanism of the excited electron-hole pair separation. The results of photodegradation showed that the A@R TiO2 NFs have the highest activity under UV-B and UV-A irradiation, being nearly 3-fold higher as compared to AEROXIDE TiO2 P25. The results in conjunction with KPFM measurements indicated that, in the heterostructure, electron-hole pairs are efficiently separated, the excited electrons stay in the anatase phase, and holes are injected to the rutile phase. When the A@R TiO2 NFs heterostructures are decorated with Pt nanoparticles (Pt-A@R TiO2 NFs), the nanocomposite is particularly active in photocatalytic hydrogen evolution from ethanol-water mixtures with a production rate of ∼8,500 μmol/h·g. Our study not only explains the role of anatase-rutile junctions in photocarrier separation, but also projects the development of other efficient photocatalytic heterostructures for green energy production and conversion.
Original language | English |
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Pages (from-to) | 1970-1979 |
Number of pages | 10 |
Journal | ACS Applied Nano Materials |
Volume | 2 |
Issue number | 4 |
DOIs | |
State | Published - 26 04 2019 |
Bibliographical note
Publisher Copyright:Copyright © 2019 American Chemical Society.
Keywords
- TiO nanofiber
- core-shell
- heterostructure
- photocatalyst
- photocatalytic hydrogen production
- photodegradation