Producing photoactive, transparent and hydrophobic SiO2-crystalline TiO2 nanocomposites at ambient conditions with application as self-cleaning coatings

被引:102
作者
Kapridaki, Chrysi [1 ]
Pinho, Luis [2 ]
Mosquera, Maria J. [2 ]
Maravelaki-Kalaitzaki, Pagona [1 ]
机构
[1] Tech Univ Crete, Sch Architectural Engn, Iraklion 73100, Greece
[2] Univ Cadiz, Fac Ciencias, Dept Quim Fis, Nanomat Grp TEP 243, Puerto Real 11510, Cadiz, Spain
关键词
SiO2-crystalline TiO2 nanocomposites; Self-cleaning products; Photoactive; Transparent and hydrophobic coatings; Oxalic acid; TITANIA-SILICA; PHOTOCATALYTIC REDUCTION; IN-SITU; NANOPARTICLES; HYDROLYSIS; MARBLE; STONE; CATALYSTS; IMPROVE; SIZE;
D O I
10.1016/j.apcatb.2014.03.042
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Nowadays, the enhancement of atmospheric pollution is dramatically increasing the presence of soiling on buildings in every city of the world. Thus, the development of photocatalysts as self-cleaning coatings is a promising challenge. The first object of this work was to develop a simple synthesis route for obtaining SiO2-crystalline TiO2 nanocomposites at ambient temperature. Thus, it meets the requirements to produce photoactive coatings on buildings and, additionally, it can be used in other applications requiring low temperature. The second objective was to gain insights into the structure of these materials and to establish the relationship between their structure and their performance as photocatalysts. The synthesis process involves mixing titanium and silicon alkoxides in the presence of oxalic acid. An organic silica oligomer is also added to reduce surface energy and consequently, to give hydrophobic properties to the material. These products were applied as a coating on marble specimens in order to investigate their effectiveness. The results obtained highlight that oxalic acid acts a chelating agent of the titanium precursor, giving rise to a homogeneous TiO2-SiO2 material. In addition and most importantly, oxalic acid produces photoactive anatase crystals at ambient temperature. From our investigation on the structure of these materials, we conclude that the formation of independent domains of TiO2 inside of SiO2 matrix, and the anatase crystal size are key factors for improving the photoactivity of the coatings. We also conclude that the oxalic acid concentration plays a crucial role in the formation of this optimum structure. (C) 2014 Elsevier B.V. All rights reserved.
引用
收藏
页码:416 / 427
页数:12
相关论文
共 54 条
[1]  
[Anonymous], 2009, 158032010 UNI EN
[2]  
[Anonymous], 2000, BILLMEYER SALTZMANS
[3]   Use of oxalate sacrificial compounds to improve the photocatalytic performance of titanium dioxide [J].
Bassaid, Salah ;
Robert, Didier ;
Chaib, Messaoud .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2009, 86 (1-2) :93-97
[4]   Nanocrystalline TiO2 by sol-gel: Characterisation and photocatalytic activity on Modica and Comiso stones [J].
Bergamonti, Laura ;
Alfieri, Ilaria ;
Lorenzi, Andrea ;
Montenero, Angelo ;
Predieri, Giovanni ;
Barone, Germana ;
Mazzoleni, Paolo ;
Pasquale, Stefania ;
Lottici, Pier Paolo .
APPLIED SURFACE SCIENCE, 2013, 282 :165-173
[5]   Surface properties and thermal stability of SiO2-crystalline TiO2 nano-composites [J].
Bonne, Magali ;
Pronier, Stephane ;
Batonneau, Yann ;
Can, Fabien ;
Courtois, Xavier ;
Royer, Sebastien ;
Marecot, Patrice ;
Duprez, Daniel .
JOURNAL OF MATERIALS CHEMISTRY, 2010, 20 (41) :9205-9214
[6]  
Conservation of Cultural, 2009, 158012010 UNI EN
[7]   Titania-silica: A model binary oxide catalyst system [J].
Davis, RJ ;
Liu, ZF .
CHEMISTRY OF MATERIALS, 1997, 9 (11) :2311-2324
[8]   Solar photocatalysis for the abatement of emerging micro-contaminants in wastewater: Synthesis, characterization and testing of various TiO2 samples [J].
Dimitroula, Helen ;
Daskalaki, Vasileia M. ;
Frontistis, Zacharias ;
Kondarides, Dimitris I. ;
Panagiotopoulou, Paraskevi ;
Xekoukoulotakis, Nikolaos P. ;
Mantzavinos, Dionissios .
APPLIED CATALYSIS B-ENVIRONMENTAL, 2012, 117 :283-291
[9]   HYDROLYSIS OF TITANIUM ALKOXIDES - MODIFICATION OF THE MOLECULAR PRECURSOR BY ACETIC-ACID [J].
DOEUFF, S ;
HENRY, M ;
SANCHEZ, C ;
LIVAGE, J .
JOURNAL OF NON-CRYSTALLINE SOLIDS, 1987, 89 (1-2) :206-216
[10]   Simple Strategy for Producing Superhydrophobic Nanocomposite Coatings In Situ on a Building Substrate [J].
Facio, Dario S. ;
Mosquera, Maria J. .
ACS APPLIED MATERIALS & INTERFACES, 2013, 5 (15) :7517-7526