A Study on Maximizing the Performance of a Concrete-Based TiO2 Photocatalyst Using Hydrophilic Polymer Dispersion

This study investigated the correlation between the dispersion stability and photocatalytic efficiency of titanium dioxide (TiO2) nanoparticles for the development of self-cleaning functional concrete. After pretreatment of P25 TiO2 with aqueous solutions of polyvinyl alcohol (PVA), polyethylene glycol (PEG), and polyethylene glycol methyl ether (PEGME), dynamic light scattering (DLS) and zeta potential measurements were performed, and as a result, a 0.1 wt% PVA solution was optimal for inhibiting aggregation, with an average hydrodynamic diameter of 1.4 µm and a zeta potential of −11 mV. In methylene blue photolysis, the reaction rate constant (k_app) was 1.71 × 10−2 min−1 (R2 = 0.98), which was improved by 11.4 times compared to the control group, and was about twice as high in the concrete specimen experiment. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) analyses confirmed an anatase-to-rutile ratio of 81:19 particle sizes of 10–30 nm, and a specific surface area of 58.985 m2·g−1. As a result, it is suggested that PVA pretreatment is a practical method to effectively improve the photocatalytic performance of TiO2-based self-cleaning concrete.