For P–Ag@AgCl–PVP–2.0, some aggregated nanoparticles appear. Plenty of monodisperse photocatalysts with smaller sizes are formed at higher concentrations of PVP; forexam- ple, P–Ag@AgCl–PVP–4.5 and P–Ag@AgCl–PVP–9.0 have products with diameters of approximately 78 nm and 40 nm, respectively