Modelling and investigation of photocatalytic and antibacterial activity on surfaces of concretes containing modified TiO2

Photocatalytic building materials can kill bacteria and viruses while cleaning organic pollutants on the surface of the material through photocatalytic and antibacterial chemicals in its structure. However, it has been observed that the photocatalytic and antibacterial performance of titanium dioxide (TiO2), which is widely used as a semiconductor in photocatalytic reactions, is limited due to its high band gap energy. In this study, it was aimed to improve the antibacterial performance of TiO2 by modifying TiO2 with metals such as silver (Ag), zinc (Zn) and copper (Cu) by mechanical alloying method and to improve the self-cleaning performance of TiO2 by obtaining changes in the band gap energy. XRD, SEM-EDS, FTIR, grain size, band gap energy change analyses were carried out on the products obtained after modification and the changes in TiO2 structure after modification were revealed. In order to measure the self-cleaning ability of the modified samples over a long period of time, self-cleaning experiments were carried out on the sample surfaces indoors for a total of 3 times at intervals of 3 months. In addition, repeated antibacterial performance tests were carried out using E. Coli and S. Aureus bacteria in accordance with ASTM 2149-01. In the experiments, mortar and concrete samples containing TiO2 without metal modification reached approximately 55% decolorization percentage in 7 days in closed environment, while up to 88% decolorization values were obtained in samples containing metal modified TiO2. The samples containing Ag modified TiO2 were the most effective content in general.