Electroconductive and catalytic performance of polypyrrole/montmorillonite/silver composites synthesized through in situ oxidative polymerization

Abstract

The present study demonstrates a simple approach to the formation of polypyrrole/montmorillonite/silver (PPy/Mt/Ag) composites via in situ oxidative polymerization of pyrrole (Py) in the presence of AgNO3 acting as a direct oxidant. The polymerization was performed in the presence of dodecylbenzenesulfonic acid, which acts as a stabilizing and doping agent. The morphological, structural, and thermal properties of PPy/Mt/Ag composites are discussed in detail and a possible formation mechanism is proposed. The electrical conductivities of the composites pressed at different pressing pressures were investigated using four-probe analyzer. X-ray diffraction, transmission electron microscopy, and scanning electron microscopy results indicated the partially exfoliated structure of the composites and Fourier transforms infrared results suggested the strong interactions between Si-O-Si groups in Mt and N-H groups in PPy chains. The addition of Mt in the PPy polymer enhanced thermal property of the polymer. The conductivity of 1.08 S cm(-1) was observed in the sample with 20 wt % Mt loading and applied pressure of 5 MPa. The composites obtained in the present study catalyze the reduction of methylene blue by sodium borohydride, achieving 92% conversion of MB to colorless within a few minutes. (C) 2017 Wiley Periodicals, Inc.