Enhanced visible-light photocatalytic activity of Ag-WO3/cement composites for organic pollutant removal

Abstract

This research focused on creating a practical cement composite with self-cleaning abilities by embedding silver-doped tungsten trioxide (Ag-WO₃) nanoparticles. We made several composites with different amounts of silver (0, 5, 7, and 15 wt.%) using a straightforward molding process. To understand the materials we created, we used techniques like like X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-Vis spectroscopy. The XRD results confirmed that the WO₃ in our composites had a monoclinic crystal structure, while SEM imaging showed that the nanoparticles were spread evenly across the cement surface. Furthermore, UV-Vis analysis proved that adding silver caused a redshift, meaning the material became better at absorbing visible light by reducing its bandgap energy. The most important finding was that the amount of silver added made a huge difference in performance. The composite with 7% Ag-WO₃ was by far the most effective. When tested under natural sunlight, it broke down 89% of a methylene blue dye pollutant in just 40 minutes. We believe this boost in performance happens because the silver particles, at this optimal amount, are perfectly dispersed and act as tiny electron traps, preventing energy waste and maximizing the photocatalytic reaction. However, adding too much silver (15%) caused the particles to clump together, which blocked light and made the composite less effective. In the end, our results show that embedding 7 wt.% Ag-WO₃ into cement is a highly effective strategy for producing smart, self-cleaning building materials that can help tackle environmental pollution.