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

Abstract

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 NaBH 4 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 NaBH 4 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. • pH-responsive AgNPs-SBA-15-PMAA catalyst was fabricated by free radical polymerization followed by Ag NPs incorporation. • Use of 1 mg catalyst for the reduction of 28 mg/L of CR dye solution. • Catalytic reduction of various toxic anionic dyes as well as the mixture of dyes within 4 min. • AgNPs-SBA-15-PMAA catalysts were separated by simple centrifugation and showed excellent reusability.