Highly Stable Self-Cleaning Paints Based on Waste-Valorized PNC-Doped TiO<sub>2</sub> Nanoparticles
Qaisar Maqbool, Orlando Favoni, Thomas Wicht, Niusha Lasemi, Simona Sabbatini, Michael Stöger‐Pollach, Maria Letizia Ruello, Francesca Tittarelli, Günther Rupprechter
Abstract
High Resolution Image Download MS PowerPoint Slide Adding photocatalytically active TiO 2 nanoparticles (NPs) to polymeric paints is a feasible route toward self-cleaning coatings. While paint modification by TiO 2 -NPs may improve photoactivity, it may also cause polymer degradation and release of toxic volatile organic compounds. To counterbalance adverse effects, a synthesis method for nonmetal (P, N, and C)-doped TiO 2 -NPs is introduced, based purely on waste valorization. PNC-doped TiO 2 -NP characterization by vibrational and photoelectron spectroscopy, electron microscopy, diffraction, and thermal analysis suggests that TiO 2 -NPs were modified with phosphate (P═O), imine species (R═N-R), and carbon, which also hindered the anatase/rutile phase transformation, even upon 700 °C calcination. When added to water-based paints, PNC-doped TiO 2 -NPs achieved 96% removal of surface-adsorbed pollutants under natural sunlight or UV, paralleled by stability of the paint formulation, as confirmed by micro-Fourier transform infrared (FTIR) surface analysis. The origin of the photoinduced self-cleaning properties was rationalized by three-dimensional (3D) and synchronous photoluminescence spectroscopy, indicating that the dopants led to 7.3 times stronger inhibition of photoinduced e – /h + recombination when compared to a benchmark P25 photocatalyst.