Silver nanoparticles impregnated pH-responsive nanohybrid system for the catalytic reduction of dyes

A pH-responsive poly(methacrylic acid) (PMAA) functionalized SBA-15 nanohybrid has been synthesized via free radical polymerization method. Furthermore, silver nanoparticles (Ag NPs) were impregnated to the polymerized SBA-15-PMAA by using co-reduction approach. The resultant AgNPs-SBA-15-PMAA catalyst was used for the reduction of various dyes using NaBH4 as the reducing agent. Compared to all other synthesized catalysts in this work as well as with the existing catalyst in the literatures, our synthesized AgNPs-SBA-15-PMAA catalyst showed significantly higher activity for the reduction of dyes due to the synergistic effect of Ag NPs and pH responsive PMAA. The effects of reaction parameters such as pH, amount of nanoparticles, and NaBH4 concentrations were also studied in detail to obtain the optimized condition for the reaction. The overall catalytic performance showed that the reduction reaction is more efficient under low pH. In addition, the catalyst could be re-used without obvious losses of catalytic activity at least more than five cycles.