Visible Light Photocatalysis of Fullerol-Complexed TiO2 Enhanced by Nb Doping
SCIE
SCOPUS
- Title
- Visible Light Photocatalysis of Fullerol-Complexed TiO2 Enhanced by Nb Doping
- Authors
- Lim, J; Monllor-Satoca, D; Jang, JS; Lee, S; Choi, W
- Date Issued
- 2014-06-25
- Publisher
- ELSEVIER SCIENCE BV
- Abstract
- Visible light photocatalysis by TiO2 nanoparticles modified with both fullerol complexation and Nb-doping (fullerol/Nb-TiO2) demonstrated an enhanced performance. Nb-doped TiO2 (Nb-TiO2) was firstly prepared by a conventional sol-gel method, and subsequently fullerol was adsorbed on the surface of Nb-TiO2. The physicochemical and optical properties of as-prepared fullerol/Nb-TiO2 were analyzed by various spectroscopic methods (TEM, EELS, XPS, and DRS). The adsorption of fullerol on Nb-TiO2 surface increased the visible light absorption through a surface-complex charge-transfer (SCCT) mechanism. Nb-doping enhanced the charge transport and induced the Ti cation vacancies that retarded the recombination of photo-generated charge pairs by trapping the electrons injected from the HOMO level of fullerol. Due to the advantage of simultaneous modification of fullerol and Nb-doping, the visible light photoactivity of fullerol/Nb-TiO2 was more enhanced than either Nb-TiO2 or fullerol/TiO2. The photocatalytic activities of fullerol/Nb-TiO2 for the reduction of chromate (CrVI), the oxidation of iodide, and the degradation of 4-chlorophenol were all higher than bare TiO2 and singly modified TiO2 (i.e., Nb-TiO2 and fullerol/TiO2) under visible light (λ>420nm). A similar result was also confirmed for their photoelectrochemical behavior: the electrode made of fullerol/Nb-TiO2 exhibited an enhanced photocurrent under visible light. On the other hand, the decay of open-circuit potential of the fullerol/Nb-TiO2 electrode after turning off the visible light was markedly slower than either that of Nb-TiO2 or fullerol/TiO2, which implies the retarded recombination of photo-generated charge pairs on fullerol/Nb-TiO2. In addition, the electrochemical impedance spectroscopic (EIS) data supported that the charge transfer resistance is lower with the fullerol/Nb-TiO2 than either Nb-TiO2 or fullerol/TiO2. This specific combination of the bulk (Nb-doping) and surface (fullerol complexation) modifications of titanium dioxide might be extended to other cases of bulk+surface combined modifications. © 2014 Elsevier B.V.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/15041
- DOI
- 10.1016/J.APCATB.2014.01.026
- ISSN
- 0926-3373
- Article Type
- Article
- Citation
- APPLIED CATALYSIS B-ENVIRONMENTAL, vol. 152-153, no. 1, page. 233 - 240, 2014-06-25
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