Synthesis of silicate sol-gel matrix embedded silver nanostructures: Efficient nanocatalyst for the reduction of 4-nitrophenol

Amine functionalized silicate sol-gel matrix embedded silver nanoparticles (Ag NPs) were prepared in the presence of beta-cyclodextrin (beta-CD-Ag-TPDT NPs) by a single-step process. The formation of sub-10 nm tetra twinned Ag nanostructures was confirmed by high resolution transmission electron microscopy studies. The reduction of 4-nitrophenol by NaBH4 was used as a model to study the catalytic efficiency of the as prepared Ag nanostructures. The 4-nitrophenol forms an inclusion complex with the hydrophobic beta-CD cavity because of the strong affinity of beta-CD to the phenyl ring moieties. The catalytic reduction of 4-nitrophenol included in the beta-CD cavity by NaBH4 was monitored in the presence of the Ag NPs using the absorption spectrophotometer by the kinetic mode analysis. The catalytic performance of the beta-CD-Ag-TPDT NPs was greatly enhanced towards the 4-nitrophenol reduction reaction. The tetra twinned shaped beta-CD-Ag-TPDT NPs with the size of sub-10 nm showed higher catalytic activity than the beta-CD-Ag NPs and Ag-TPDT NPs. (C) 2012 Elsevier B.V. All rights reserved.