Reduced TiO2; Rutile; Ni(II)-porphyrin; Methylene blue photodegradation; Visible irradiation; Sol–gel process
Abstract :
[en] H2-reduced rutile-TiO2 xerogel (Ti-700), obtained via the sol–gel process, was found to strongly adsorb the Ni(II)-5,10,15,20-tetrakis(4-carboxyphenyl)-porphyrin (NiTCPP) from a methanolic solution, despite its
very low specific surface area (SBET ≈ 2 m2 g−1). UV/vis spectroscopy analysis showed that after calcination
at 700 ◦C and reduction under H2 flow at 400 ◦C, the TiO2-xerogel increased its NiTCPP-adsorption capacity
by surface area unit by up to 120 times. The effect of the porphyrin presence in the catalytic performances
of TiO2-xerogels was studied through three kinetics models: (i) the pseudo-first-order kinetic model;
(ii) the pseudo-second-order kinetic model, which are used to describe the adsorption rate based on
the adsorption capacity of the catalysts; and (iii) the Langmuir–Hinshelwood kinetic model which is
used to describe the photocatalytic degradation rate of methylene blue (MB). A significant improvement
in the efficiency of Ti-700 was observed after the porphyrin-adsorption process (NiTCPP/Ti-700): MB-adsorption
capacity at equilibrium and the apparent MB-photoconversion constant, kapp, of NiTCPP/Ti-700 were both up to 2 times higher than those observed for the Ti-700.
Disciplines :
Materials science & engineering Chemistry Chemical engineering
Author, co-author :
Páez Martínez, Carlos ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Lambert, Stéphanie ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Poelman, Dirk; Ghent University > Department of Solid State Sciences > Lumilab
Pirard, Jean-Paul ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Génie catalytique
Heinrichs, Benoît ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Nanomatériaux et interfaces
Language :
English
Title :
Improvement in the methylene blue adsorption capacity and photocatalytic activity of H2-reduced rutile-TiO2 caused by Ni(II)porphyrin preadsorption
Publication date :
2011
Journal title :
Applied Catalysis B: Environmental
ISSN :
0926-3373
eISSN :
1873-3883
Publisher :
Elsevier Science, Amsterdam, Netherlands
Volume :
106
Pages :
220-227
Peer reviewed :
Peer Reviewed verified by ORBi
Funders :
F.R.S.-FNRS - Fonds de la Recherche Scientifique [BE] FRFC - Fonds de la Recherche Fondamentale Collective [BE] MRW - Ministère de la Région wallonne [BE] FWO - Fonds Wetenschappelijk Onderzoek Vlaanderen [BE] Belgian Interuniversity Attraction Pole INANOMAT (IAP-P6/17)