skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Light-induced bioactive TiO{sub 2} surface

Abstract

We have achieved bioactivity enhancement of nanostructured titania using ultraviolet (uv) light irradiation. The titania coating fabricated by nanoparticle plasma spraying consists of a nano-TiO{sub 2} coating surface composed of primarily nanosized anatase. After irradiation by ultraviolet light in air for 24 h, the as-sprayed and UV-irradiated TiO{sub 2} coatings were soaked in simulated body fluids (SBF) to investigate their bioactivity. The UV-illuminated TiO{sub 2} coating induced bonelike apatite formation on the surface whereas no apatite could be detected on the as-sprayed TiO{sub 2} coating. The formation of oxygen vacancies at the two-coordinated bridging sites by UV illumination is believed to result in the conversion of the corresponding Ti{sup 4+} sites to Ti{sup 3+} sites, which are favorable to the dissociation of water in the SBF and subsequent formation of Ti-OH and an apatite layer. Our results reveal that the surface bioactivity of titania coatings can be induced by UV illumination.

Authors:
; ; ;  [1];  [2];  [2]
  1. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China) and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China)
  2. (China)
Publication Date:
OSTI Identifier:
20778531
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 88; Journal Issue: 1; Other Information: DOI: 10.1063/1.2162687; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AIR; APATITES; BODY FLUIDS; CRYSTALS; DISSOCIATION; IRRADIATION; LAYERS; NANOSTRUCTURES; OXYGEN; PLASMA; SPRAYED COATINGS; SURFACE TREATMENTS; TITANIUM IONS; TITANIUM OXIDES; ULTRAVIOLET RADIATION; VACANCIES; VISIBLE RADIATION

Citation Formats

Liu Xuanyong, Zhao Xiaobing, Ding Chuanxian, Chu, Paul K., Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong. Light-induced bioactive TiO{sub 2} surface. United States: N. p., 2006. Web. doi:10.1063/1.2162687.
Liu Xuanyong, Zhao Xiaobing, Ding Chuanxian, Chu, Paul K., Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, & Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong. Light-induced bioactive TiO{sub 2} surface. United States. doi:10.1063/1.2162687.
Liu Xuanyong, Zhao Xiaobing, Ding Chuanxian, Chu, Paul K., Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong. Mon . "Light-induced bioactive TiO{sub 2} surface". United States. doi:10.1063/1.2162687.
@article{osti_20778531,
title = {Light-induced bioactive TiO{sub 2} surface},
author = {Liu Xuanyong and Zhao Xiaobing and Ding Chuanxian and Chu, Paul K. and Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 and Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong},
abstractNote = {We have achieved bioactivity enhancement of nanostructured titania using ultraviolet (uv) light irradiation. The titania coating fabricated by nanoparticle plasma spraying consists of a nano-TiO{sub 2} coating surface composed of primarily nanosized anatase. After irradiation by ultraviolet light in air for 24 h, the as-sprayed and UV-irradiated TiO{sub 2} coatings were soaked in simulated body fluids (SBF) to investigate their bioactivity. The UV-illuminated TiO{sub 2} coating induced bonelike apatite formation on the surface whereas no apatite could be detected on the as-sprayed TiO{sub 2} coating. The formation of oxygen vacancies at the two-coordinated bridging sites by UV illumination is believed to result in the conversion of the corresponding Ti{sup 4+} sites to Ti{sup 3+} sites, which are favorable to the dissociation of water in the SBF and subsequent formation of Ti-OH and an apatite layer. Our results reveal that the surface bioactivity of titania coatings can be induced by UV illumination.},
doi = {10.1063/1.2162687},
journal = {Applied Physics Letters},
number = 1,
volume = 88,
place = {United States},
year = {Mon Jan 02 00:00:00 EST 2006},
month = {Mon Jan 02 00:00:00 EST 2006}
}
  • Highlights: • Both surface plasmon resonance and band-gap excitation were used for H{sub 2} production. • Au/Gr/TiO{sub 2} composite photocatalyst was synthesized. • Au/Gr/TiO{sub 2} exhibited enhancement of light absorption and charge separation. • H{sub 2} production rate of Au/Gr/TiO{sub 2} was about 2 times as high as that of Au/TiO{sub 2}. - Abstract: H{sub 2} production over Au/Gr/TiO{sub 2} composite photocatalyst induced by surface plasmon resonance of Au and band-gap excitation of TiO{sub 2} using graphene (Gr) as an electron acceptor has been investigated. Electron paramagnetic resonance study indicated that, in this composite, Gr collected electrons not only frommore » Au with surface plasmon resonance but also from TiO{sub 2} with band-gap excitation. Surface photovoltage and UV–vis absorption measurements revealed that compared with Au/TiO{sub 2}, Au/Gr/TiO{sub 2} displayed more effective photogenerated charge separation and higher optical absorption. Benefiting from these advantages, the H{sub 2} production rate of Au/Gr/TiO{sub 2} composite with Gr content of 1.0 wt% and Au content of 2.0 wt% was about 2 times as high as that of Au/TiO{sub 2}. This work represents an important step toward the efficient application of both surface plasmon resonance and band-gap excitation on the way to converting solar light into chemical energy.« less
  • Graphical abstract: - Highlights: • TPA impregnation on TiO{sub 2} particles was done at different initial pH values. • Powders characterization evidenced the possible existence of TPA–TiO{sub 2} complexes. • Keggin anion complexed on TiO{sub 2} would be responsible of visible light absorption. - Abstract: TiO{sub 2} particles prepared by the sol–gel method were impregnated at different pH values (1.0, 2.0, 5.0 and 10.0) with a water–ethanol solution (50% V/V) of tungstophosphoric acid (TPA) (0.012 M). Similar preparation was carried out to synthesize TiO{sub 2} impregnated with [WO{sub 4}]{sup 2−} (TiW). These materials were characterized by different techniques such asmore » UV–vis diffuse reflectance spectroscopy (UV–vis DRS), magic angle spinning nuclear magnetic resonance of {sup 31}P ({sup 31}P MAS NMR), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Fourier transform Raman spectroscopy (FT-Raman). Results revealed that TPA–TiO{sub 2} materials exhibit visible light absorption only when impregnation was done at pH 1.0 (TiTPA1) and 2.0 (TiTPA2). TiW powder did not show visible light absorption. XRD patterns show the presence of peaks at 2θ = 25.4° (1 0 1), 37.9° (0 0 4), 47.8° (2 0 0) and 54.3° associated to the anatase phase. Solid NMR, FT-IR and FT-Raman characterization showed that TiTPA1 and TiTPA2 samples contain Keggin ([PW{sub 12}O{sub 40}]{sup 3−}) and lacunary anions ([PW{sub 11}O{sub 39}]{sup 7−}) respectively. On the other hand, FT-Raman results revealed a blue shifting and broadening of the band at 141 cm{sup −1} corresponding to anatase TiO{sub 2} and moreover, a broadening of bands at 900–1100 cm{sup −1} attributed to Keggin structures of TPA. Both spectral changes could be related to the formation of a surface complex between the Keggin anion of TPA and TiO{sub 2} surfaces. This interaction should be responsible for visible light absorption.« less
  • Glasses in SiO{sub 2} {center_dot} CaO {center_dot} P{sub 2}O{sub 5} and SiO{sub 2} {center_dot} CaO {center_dot} P{sub 2}O{sub 5} {center_dot} MgO systems have been prepared by a sol-gel synthesis procedure. The calcined glasses have been characterized by XRD, N{sub 2} adsorption, Hg porosimetry, XPS and TEM have been also subjected to in vitro tests (immersion in a simulated body fluid) to evaluate their bioactivity. The presence of magnesium in the glasses increases the surface area and porosity, but is retards the formation of an apatite layer on the surface of glasses in the in vitro test. The XPS reveals thatmore » the surfaces of the glasses are richer in phosphorus and poorer in calcium than the bulk, whereas the magnesium, if present, associates preferentially to phosphorus at the glass surface. The TEM shows the presence of apatite-like calcium phosphate domains in the magnesium -free glasses, which are barely detected in the glasses, which contain this element. These apatitic domains are proposed to be the nucleation centers for the crystallization of apatite in the in vitro tests.« less
  • Sr{sub 2}TiO{sub 4}:Cr complexes are found to possess photochromism. After the photochromism, the catalytic performance of the complexes for H{sub 2} generation increases markedly. In fact, it was found that the performance increased more than 20 times compared to the original Sr{sub 2}TiO{sub 4}: 10 mol % Cr complex. These results suggest that it is worthwhile searching and optimizing visible-light-sensitive photocatalysts by investigating possible photochromism.
  • All available thermodynamic and phase diagram data have been critically assessed for all phases in the MnO-TiO[sub 2], MgO-TiO[sub 2], FeO-TiO[sub 2], Ti[sub 2]O[sub 3]-TiO[sub 2], Na[sub 2]O-TiO[sub 2], and K[sub 2]O-TiO[sub 2] systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable thermodynamic and phase diagram data have been simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid slag as a function of composition and temperature and equations for the Gibbs energies of all compounds as functions of temperature. The modified quasichemical model wasmore » used for the molten slag phases.« less