Stephanie D Lambert
University of Liege, Belgium
Title: Highly efficient low-temperature n-doped TiO2 catalysts for visible light photocatalytic applications
Biography
Biography: Stephanie D Lambert
Abstract
In this work, an aqueous titania sol-gel synthesis is doped with nitrogen precursor to extend its activity towards visible region. Three N-precursors are used: urea, ethylenediamine and triethylamine. Different molar ratios have been tested for each dopant. Results showed the formation of anatase-brookite TiO2 nanoparticles of 6-8 nm with a specific surface area between 200 and 275 m2g-1 for the urea and triethylamine series. Concerning the ethylenediamine series, the formation of rutile phase is observed when the amount of ethylenediamine increases due to the addition of nitric acid in order to maintain the peptization process during the synthesis [1]. In this series, TiO2 nanoparticles of 6-8 nm are also obtained with a specific surface area between 185 and 240 m2g-1.Combination of XPS and diffuse reflectance measurements suggests the incorporation of nitrogen in TiO2 materials through Ti-O-N bonds allowing absorption in visible region. Catalytic tests showed a marked improvement of performance under visible radiation for all doped catalysts in the remediation of polluted water with p-nitrophenol. In this case, nitrogen doping can reduce the band gap by creating an intermediate band for the electrons below the conduction band or above the valence band, allowing activity in the visible range. The best doping, regarding cost, activity and ease of synthesis (urea precursor with a molar urea/Ti precursor ratio of 2), is up-scaled to a volume of 5 L and compared to commercial Evonik P25 material. This urea-doped large scale catalyst showed analogous properties as the lab-scale corresponding synthesis and a photoactivity 4 times higher than commercial Evonik P25 photocatalyst.
Recent Publications
1. Mahy J G, Cerfontaine V, Poelman D, Devred F, Gaigneaux E, et al. (2018) Highly efficient low temperature N-doped TiO2 catalysts for visible light photocatalytic applications. Materials 584.
2. Benhebal H, Benrabah B, Ammari A, Madoune Y and Lambert SD (2018) Structural and optoelectronic properties of SnO2 thin ï¬lms doped by group-1A elements. Surface Review and Letters 25:1850007-1-1850007-6.
3. Ghrab S, Benzina M and Lambert S D (2017) Copper adsorption from waste water using bone charcoal. Advances in Materials Physics and Chemistry 7:139–147.
4. Mahy J G, Claude V, Sacco L and Lambert S D (2017) Ethylene polymerization and hydrodechlorination of 1,2-dichloroethane mediated by nickel(II) covalently anchored to silica xerogels. Journal of Sol-Gel Science and Technology 81:59–68.
5. Claude V, Solís Garcia H, Wolfs C and Lambert S D (2017) Elaboration of an easy aqueous sol-gel method for the synthesis of micro- and mesoporous γ-Al2O3 supports. Advances in Materials Physics and Chemistry 7:294–310.