The influence of rapid heat treatment in still air on the photocatalytic activity of titania photocatalysts for phenol and monuron degradation

Zs Pap, V. Danciu, Zs Cegléd, Á Kukovecz, A. Oszkó, A. Dombi, K. Mogyorósi

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Abstract

Titanium dioxide photocatalysts were prepared by a new synthesis method that involves rapid heating with short and medium exposures of the sol-gel prepared amorphous starting materials at different temperatures and calcination times (RHSE and RHME series). Samples were also synthesized using conventional calcination methods (applying slow heating and long exposure times, SHLE series). Both sets of samples were characterized by various methods, such as TG-DTA, XRD, SEM, TEM, DRS, FT-IR, TOC and XPS techniques and by sedimentation experiments. The RHSE and RHME samples have good crystallinity and consist of anatase and rutile mixtures. The photocatalytic activity of catalysts was studied in suspensions using phenol and monuron as model substrates. The best UV performance was found for the RHME sample prepared at 600°C with 60min of exposure. This sample has high UV activity and is comparable to Aeroxide P25 TiO2 reference photocatalyst for both substrates. The RHSE and RHME samples significantly exceeded the performance of SHLE samples. The loss of surface OH groups during long time calcination was assumed to have a negative effect on the activity of SHLE samples due to a high degree of aggregation of the particles in aqueous solutions. The improved photocatalytic performance is attributed to the higher level of absorption of light in the near-UV range. This new more economic treatment strategy could have major impact on materials engineering of UV and VIS active photocatalysts prepared via sol-gel methods, especially using acetic acid and aqueous solution of ammonia.

Original languageEnglish
Pages (from-to)461-470
Number of pages10
JournalApplied Catalysis B: Environmental
Volume101
Issue number3-4
DOIs
Publication statusPublished - Jan 14 2011

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Keywords

  • Anatase
  • Monuron
  • Nanoparticles
  • Phenol
  • Photocatalysis
  • Rapid crystallization
  • Rutile
  • Sol-gel method
  • Titania
  • UV irradiation

ASJC Scopus subject areas

  • Catalysis
  • Environmental Science(all)
  • Process Chemistry and Technology

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