Efficient functionalization of poly(styrene) beads immobilized metal nanoparticle catalysts for the reduction of crystal violet

Abstract

Three types of new bead-shaped heterogeneous nanoparticle (NP) catalysts were synthesized by simplified procedures and studied for continuous reduction of crystal violet (CV) dye. The stabilizing agent, viz., 2-acryloxyethyltrimethyl ammonium chloride (PAC) was functionalized efficiently onto the surface of insoluble poly(styrene)-co-(vinyl benzyl chloride) beads (PS–PVBC) through surface-initiated atom transfer radical polymerization (SI-ATRP) to obtain insoluble bead matrix having intense surface functional groups labelled as PS–PVBC-g-PAC. These PS–PVBC–PAC beads in turn were used as a common matrix for individual immobilization of AgNPs, AuNPs and PdNPs by following the simple chemical reaction/reduction methods to yield the corresponding bead-shaped heterogeneous NP catalysts, viz., PS–PVBC-g-PAC–AgNPs, PS–PVBC-g-PAC–AuNPs and PS–PVBC-g-PAC–PdNPs. These catalysts were characterized by UV–Vis, FT-IR, SEM/EDAX and HRTEM techniques. The catalytic activity of these three types of catalysts were examined through the reduction of CV using NaBH ₄ as a reducing agent and it was observed that all these catalysts effectively accelerated the reaction. The superior catalyst, viz., PS–PVBC-g-PAC–AuNPs was again used for detail kinetic studies of the same reduction reaction.