The Preparation of Sulfonated PS Microspheres Supported nZVFe/Ag Bimetals and Its Using in the Catalytic Reduction of 3-CP

Based on soapless emulsion polymerization and dispersion polymerization, two kinds of sulfonated polystyrene microspheres were synthesized. Taking them as carrier, four kinds of SPS@Ag microspheres were prepared, i.e. SPS1@Ag(NaBH4), SPS1@Ag(PVP), SPS2@Ag(NaBH4), and SPS2@Ag(PVP), by NaBH4/PVP reduction methods. SPS1@Ag(PVP) was the best one, the nZVAg was about 20 nm and uniformly supported on SPS; the loading capacity was maximum. SPS supported nZVFe/Ag (SPS@nZVFe/Ag) was successfully prepared by chemical reduction. Part of nZVI was homogeneously covered on the surface of SPS1@nZVAg and others existed as particles with size of 30–100 nm. The loading content of nZVI was 0.254 g/g. Taking 3-chlorophenol (3-CP) as model pollutant, the reactivity of SPS@nZVFe/Ag was carefully studied. The influence of the mole ratio of Ag/Fe and initial solution pH on the reactivity of SPS@nZVFe/Ag were investigated. At optimal reaction condition, 97% 3-CP in 50 mL 20 mg/L 3-CP solution (pH = 5) was reduced into phenol by about 0.344 g SPS@nZVFe/Ag (Ag/Fe = 0.041) at 20 °C, under stirring (110 r/min) within 10 min. The reaction was agreed with the pseudo first-order kinetics model. The reaction rate was very fast and the Kobs was 0.684 min−1, which should attribute to both the electrochemical effect between Fe0 and Ag0, and the good hydrophily of SPS@nZVFe/Ag due to the –HSO3 group on the carrier. In generally, SPS@nZVFe/Ag showed excellent reductive activity which suggested SPS@nZVFe/Ag had high potential practical application value in the reductive degradation of chlorophenol pollutant.