6533b7d6fe1ef96bd126728a
RESEARCH PRODUCT
A sustainable replacement for TiO2 in photocatalyst construction materials: Hydroxyapatite-based photocatalytic additives, made from the valorisation of food wastes of marine origin
Russell BinionsPaula M. L. CastroDavid M. TobaldiRobert C. PullarManfredi SaeliManfredi SaeliClara Piccirillosubject
Strategy and ManagementSettore ING-IND/22 - Scienza e Tecnologia dei MaterialiWaste valorisationSettore ICAR/10 - Architettura Tecnica02 engineering and technology010501 environmental sciencesengineering.materialConstruction material; Hydroxyapatite; NHL mortar; Photocatalysis; Sustainable material; Waste valorisation01 natural sciencesIndustrial and Manufacturing Engineering12. Responsible consumptionHydroxyapatitePhotocatalysiSustainable materialCoating11. SustainabilitySettore ICAR/08 - Scienza delle CostruzioniPhotocatalysisNOx0105 earth and related environmental sciencesGeneral Environmental SciencePollutantSettore CHIM/03 - Chimica Generale e InorganicaNHL mortarWaste managementRenewable Energy Sustainability and the EnvironmentHydraulic limeSettore CHIM/07 - Fondamenti Chimici delle TecnologieBuilding and ConstructionConstruction material021001 nanoscience & nanotechnologyConstruction industry13. Climate actionengineeringPhotocatalysisEnvironmental scienceValorisationMortar0210 nano-technologydescription
The use of waste materials and by-products in building materials is of increasing importance to improve sustainability in construction, as is the incorporation of photocatalytic materials to both combat atmospheric pollution and protect the structures and façades. This work reports the innovative use of photocatalytic hydroxyapatite (HAp) based powders, derived from Atlantic codfish bone wastes, as an additive to natural hydraulic lime mortars. HAp is the main component of bone, and hence is non-toxic and biocompatible. This is the first time that such a calcium phosphate-based photocatalyst, or indeed any fish/marine derived wastes, have been added to building materials. A key factor is that this HAp-based photocatalyst contains only 1 wt% TiO2, the material usually used as a photocatalyst in construction materials. As we only add 1–5 wt% of our total HAp-based material to the mortar, this means our photocatalytic mortars only contain 0.01–0.05 wt% titania (100–500 ppm), two orders of magnitude less than the quantities of 2–10 wt% TiO2 which are usually needed. Our photocatalyst is made from a sustainable waste stream by simple solution and thermal processing, and thus with a much smaller impact on the environment. Specimens were made by either traditional intermixing techniques, or by a post-curing coating procedure. All showed gas-phase photocatalytic activity for abatement of NOx pollutants under solar light. With intermixing, NOx abatement of 6.3–8.3% was observed. However, for coated mortars, superior NOx conversion rates were achieved of 7.1% and 23.8%, with 1 and 5 wt% additions, respectively. These results show the potential of this naturally-derived photocatalyst for applications in the construction industry, leading to lower atmospheric pollution and the creation of more durable/lower maintenance building façades, and environmentally sustainable materials for the preservation of cultural heritage.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-08-20 |