With the increasing air pollutants particularly in the cities the deteriorating conditions of the buildings accelerate. One of the non-invasive and cheap promising ways how to prevent the buildings against the aged processes caused by biological pollutants or smog exhalation is the innovation of suitable photocatalytic coatings. This work focuses on the characterization of prepared photocatalytic nanocomposite TiO2-SiO2 system to be applied on the building objects in order to improve a quality of their surfaces. The structure and the texture characterization of prepared nanocomposite were determined by electron microscopy (SEM, TEM + EDS). The photocatalytic activity of the composite was determined considering the self-cleaning ability and the antibacterial activity. For self-cleaning characterization the methylene blue degradation was measured. These self-cleaning properties were tested on the various types of supports, which are commonly used in the building facades. To estimate antibacterial and biocidal activity the Gram-negative bacterium Escherichia coli and the gram-positive bacteria Staphylococcus aureus were used. Both methods were done according to standard ISO tests. Next to the laboratory testing the application of the composite under the real condition was implemented. There were treated parts of the concrete outside wall with the composite and after more than one year the colour changed analysis of the wall surface was characterized.

Photocatalytic concrete screeds with self-cleaning and antimicrobial function have been developed and tested. These building materials contain sand grains with deposited composite TiO2/SiO2 layers. Two types of the screeds, grey and white, were prepared and their photoactivity and material characteristics were compared. Commercial TiO2 photocatalysts from several manufacturers were employed. Effects of different parameters, such as temperature of the coated sand calcination, humidity, and surface abrasion, were followed. Mechanical properties of the screeds were analyzed by SEM/XRD microscopy. Photocatalytic activity was tested by means of NOx oxidation (ISO norm 22197-1/2007). Antibacterial activity was evaluated by modified ISO norm 27447/2009 with Bacillus subtilis as a model organism.

This article presents research and development on innovative photoactive admixtures for concrete and cement-based plasters for the finishing of concrete surfaces finished this year. The goal of the development was to provide the resulting surfaces of these newly developed materials with a self-cleaning ability stemming from photocatalytic reaction during exposure to UV radiation. The specific function of all these products is based on the photocatalytic oxidative mineralization of all organic structures present on the surface, i.e., their gradual transformation into the final simple inorganic compounds, which are carbon dioxide, water and the corresponding mineral acids. This research and development was carried out as part of a project supported by the Czech Ministry of Industry and Trade, in the TRIO programme; and in cooperation of BETOSAN s.r.o., the Technical University of Liberec, the Institute of Inorganic Chemistry of the Czech Academy of Sciences and the J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences. The first type of developed material is a photocatalytically active admixture in powder form, allowing the preparation of concrete surfaces with photocatalytic properties. The second type of developed material is a photocatalytically active cement-based plaster, intended primarily for application to a concrete substrate. Two final versions of both materials were developed. In the case of the plaster this means preparation of two colour variants, specifically white and grey. For the powder concrete admixture two types with different application procedures were developed. This means one version of admixture mixed throughout the entire volume of the concrete and second variant applied only in the surface layer of the concrete. We anticipate mainly exterior applications on the self-cleaning outer shell of buildings, as well as treatment of the surface layer of various structures such as bridges, noise barriers, traffic barriers and tunnels. The developed materials can also be used in interiors under specific conditions, with anticipated uses in the health care and food processing industries.

This article presents research and development on innovative photoactive admixtures for concrete and cement-based plasters for the finishing of concrete surfaces. The goal is to provide the resulting surfaces of these newly developed materials with a self-cleaning ability stemming from photocatalytic reaction during exposure to UV radiation. This research and development is currently underway as part of a project supported by the Czech Ministry of Industry and Trade, in the TRIO programme; and in cooperation with BETOSAN s.r.o., the Technical University of Liberec, the Institute of Inorganic chemistry of the Czech Academy of Sciences and the J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences. The first type of material under development is a photocatalytically active admixture in powder form, allowing the preparation of concrete surfaces with photocatalytic properties. The second type of material under development is a photocatalytically active cement-based plaster, intended primarily for application to a concrete substrate. The preparation of two or more final versions is to be expected for both types of materials. In the case of the plaster this includes the preparation of two colour variants, specifically white and grey. For the powdered cement admixture we expect the preparation of various types based on their application. This could mean different types of admixtures mixed throughout the entire volume of the concrete or only in the surface layer of the concrete. We envisage exterior applications on the self-cleaning outer shell of buildings, as well as treatment of the surface layer of various structures such as bridges, noise barriers, traffic barriers and tunnels. The materials created could also be used in interiors under specific conditions, with anticipated uses in the health care and food processing industries.