First, we present a study of the roles of PVP in the synthesis of P-Ag@AgCl. Fig. 1(A–D) shows the effect of PVP on the morphology of the products syn- thesized at PVP concentrations of 0 mg/mL, 2 mg/mL, 4.5 mg/mL and 9.0 mg/mL, and these products are noted as P-Ag@AgCl–PVP-0 to 9.0.