Enhancing the photocatalytic properties of TiO2 by coupling with carbon nanotubes and supporting gold

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Huihu H Wang (Author) Other; Shijie J Dong (Author) Other; Ying Chang (Author) Other; Joaquim L Faria (Author) FEUP

Journal

Title: Journal of Hazardous Materials

Vol. 235

Pages: 230-236

ISSN: 0304-3894

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 37 Citations

ISI Web of Science

Scopus - 40 Citations

Scientific classification

FOS: Engineering and technology > Civil engineering

Other information

Authenticus ID: P-002-4EZ

DOI: 10.1016/j.jhazmat.2012.07.050

Abstract (EN): The photodegradation of methylene blue in aqueous solutions is studied using various photocatalysts, including neat TiO2, CNT-TiO2, Au-TiO2, and Au-CNT-TiO2 composites MB. Materials were synthesized and extensively characterized by XRD, TEM, DRFIT spectroscopy, N-2 adsorption-desorption isotherms, as well as diffuse reflectance UV-vis spectroscopy. By using CNT-TiO2 composite as catalysts, it was found that CNT act as adsorbent and photosensitizer to improve the photoactivity of neat TiO2. Among the CNT-TiO2 composites with different CNT weight ratio (0.2-20%), the 2%CNT-TiO2 shows the best photoactivity. When CNT content is larger than 2%, the surplus CNT may absorb and scatter light photons. Combined with the decrease of TiO2 amount in composite, the photoactivity is reduced. To further improve the photoactivity of 2%CNT-TiO2, different Au loads varying from 0.25% to 1% were introduced by the deposition-precipitation method. The 0.25%Au-2%CNT-TiO2 composite had the highest photoactivity. The increase in activity was explained by the surface plasmon resonance of Au that makes the composite to absorb more photons than the 2%CNT-TiO2, thus overcoming the disadvantages of surplus CNT addition. On the other hand, 0.25%Au-2%CNT-TiO2 composite also presents higher activity than 0.25%Au-TiO2 due to higher adsorption capacity provided by CNT introduction. The addition of CNT and Au simultaneously has a much stronger synergic role than when each of them is introduced individually.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7