Self-cleaning cementitious materials, particularly with TiO2-based photocatalytic coatings, offer significant benefits by reducing surface deterioration and maintenance requirements, even in harsh urban environments. Despite the growing interest in self-cleaning cementitious materials, an international standard test method to calculate their efficiency has not yet been established for this specific type of subs...
Building façades are affected by atmospheric pollution and other external agents that can impact aesthetic aspects and lead to the appearance of anomalies with impacts on the durability and performance of materials. The reduction in maintenance costs and the preservation of the original characteristics of coatings make the use of photocatalytic semiconductor materials highly attractive, particularly for the con...
A poluição atmosférica é um problema que afeta os centros urbanos. Uma abordagem inovadora para mitigar este problema é a utilização de nanopartículas de dióxido de titânio (TiO2) em pavimentos betuminosos. A aplicação do TiO2 confere ao pavimento capacidades fotocatalíticas, permitindo a degradação de poluentes atmosféricos na presença de luz solar. O método de revestimento por pulverização é considerado o mai...
Controlling atmospheric pollution is a challenge for society. Air pollutants, such as NO and NO2, resulting from the combustion of fuels in the air, can cause acid rain and pose health risks to human beings. Using semiconductor nanoparticles, e.g., TiO2, in Asphalt Mixtures (AM) to photodegrade NOx is a promising alternative for air cleaning in urban cities. Asphalt pavements are ideal materials for that due to...
As fachadas dos edifícios são expostas à poluição atmosférica e outros agentes externos que afetam os seus aspetos estéticos e acarretam o aparecimento de anomalias com impacto na durabilidade e desempenho dos materiais. A manutenção das fachadas é um processo complexo, que envolve altos custos, riscos para os trabalhadores, além do uso intensivo de recursos, como água e energia. Desenvolver painéis de betão au...
A qualidade do ar em áreas urbanas é um problema global que afeta a saúde pública e o meio ambiente e é muito afetada pelo trafego de veículos automóveis. Este estudo avalia a eficácia da amostragem passiva para medir a concentração de dióxido de nitrogênio (NO2) na cidade de Guimarães da região do Minho no noroeste de Portugal. Utilizando filtros de celulose impregnados com uma solução absorvedora, as amostras...
The use of titanium dioxide (TiO2) nanoparticles on asphalt pavements as surface coating has been the subject of study since these coatings can degrade air pollutants through a photocatalytic process. However, the environmental impacts associated with the functionalization of nanoparticles on the pavement are still unknown. Therefore, this research aims to perform a Life Cycle Assessment (LCA) of an asphalt pav...
This study investigates the effect of iron-modified nano-TiO2, using the co-precipitation method with different concentrations of FeCl3 (0.1, 1, and 10%), to improve its photocatalytic properties for outdoor applications. To this end, modified and unmodified nano-TiO2 were characterized using different techniques. The optical properties were characterized by diffuse reflectance spectroscopy (DRS) followed by ba...
[Excerto] Photocatalytic asphalt mixtures have gained attention as a possible alternative to mitigate the air pollution in urban areas. The asphalt surface when functionalized with nano-TiO2 can reduce nitrogen oxides (NOx), a harmful pollutant emitted by vehicles that contributes to problems such as acid rain and public health concerns
This research reports a simple, innovative, and low-cost doping method of TiO2 nanoparticles presenting the effects of calcination and the weight ratio of TiO2:FeCl3 (1:0.33–1:4.5). The photocatalytic activity of the nanomaterials was investigated by decolorizing Rhodamine B (RhB) dye in an aqueous solution. The main results showed that there is anatase-to-rutile transformation after the calcination process. Th...