abstract
Recent advances in nano-technology and nano-additives can give enhanced properties to natural hydraulic lime (NHL); creating a multifunctional material. We have prepared a novel nanocomposite, made of a commercial mortar with 1 wt% and 5 wt% added titania nanoparticles (NPs). These TiO2 NPs are themselves doped with 1 mol% silver, to give the material enhanced photocatalytic and antimicrobial properties. The Ag-doped TiO2 NPs were made "from a simple, costs effective, aqueous green nanosynthesis process, and the end material only contains 0.01-0.05% Ag. As this mortar is intended to both combat atmospheric pollution, and create more durable/lower maintenance building fa ades (plastering and finishing) by limiting attack from microorganisms and pollutants, its photocatalytic anti-pollution activity under solar and visible (no UV) light for nitrous oxide (NOx) and volatile organic compound (VOC) removal was studied. The addition of dopants did not significantly alter the physical properties or curing of the mortar, while it showed excellent photocatalytic activity under sunlight, The mortars with only 1 and 5 wt% additives degraded 10.6% and 21% NO after 45 mins, respectively, comparing well to a value of 50% for a pure TiO2/Ag+ sample. They also degraded VOCs under visible light, of the kind used for lighting inside buildings, with no UV component. As the NPs are contained in the whole of the mortar layer, not just as a coating, if the surface is chipped or damaged this mortar will not loose its photocatalytic capabilities. (C) 2017 Elsevier Ltd. All rights reserved.
keywords
TITANIUM-DIOXIDE; TIO2 PHOTOCATALYSIS; BUILDING-MATERIALS; OPTICAL-PROPERTIES; AIR; FUNDAMENTALS; CONSTRUCTION; PURIFICATION; NANOPOWDERS; CHEMISTRY
subject category
Construction & Building Technology; Engineering; Materials Science
authors
Saeli, M; Tobaldi, DM; Rozman, N; Skapin, AS; Labrincha, JA; Pullar, RC
our authors
David Maria Tobaldi
Researcher
João António Labrincha Baptista
Full professor
Rob Pullar
Collaboratoracknowledgements
The authors wish to thank the company Saint-Gobain Weber Portugal, S.A. (Zona Industrial de Taboeira, 3800-055 Aveiro, Portugal) for providing natural hydraulic lime (Weber Rev 158), with particular thanks to Eng. Luis Silva, Eng. Nuno Vieira and Eng. Pedro Sequeira. M. Saeli wishes to thank the University of Palermo for supporting this work (Post-doc fellowships funded by the Benefict 5x1000, Decreto N. 447/2013). R.C. Pullar wishes to thank the FCT Ciencia 2008 programme and FCT grant SFRH/BPD/97115/2013. N. Rozman and A. Sever kapin thank Slovenian research agency (ARRS) for the financial support (Program P2-0273). This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement.