Highly loaded silver nanoparticle‐modified monodispersed polystyrene composite microspheres (PS/Ag) for rapid catalytic reduction of methylene blue

Abstract In this research, monodispersed polystyrene (PS) microspheres were prepared by dispersion polymerization. PS microspheres decorated with silver nanoparticles (PS/Ag composite microspheres) were synthesized by a modified chemical plating method with water as the synthesis medium. The microspheres at each stage were characterized by Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), UV–visible spectroscopy (UV–vis), field‐emission scanning electron microscopy (FESEM), and energy‐dispersive spectrometer (EDS). The reduction of methylene blue (MB) was carried out with PS/Ag composite microspheres as a catalyst and NaBH 4 as a reducing agent. The results showed that the MB dye was reduced to colorless within 180 s. The reduction of the MB dye followed pseudo‐first‐order kinetics with an apparent rate constant (K app ) value of 0.01425 s −1 . Control experiments were also carried out by adding microspheres from each chemical plating pretreatment stage to the MB, without PS/Ag composite microspheres. The catalytic activity of the PS/Ag composite microspheres was high after five consecutive cycles of recovery, showing promising reusability. The catalytic activity of the prepared PS/Ag catalysts was superior to other catalysts for the reduction of MB.