Fabrication of ultrathin nanozeolite film modified electrodes and their electrochemical behavior

Abstract

Ultrathin nanozeolite films were prepared on the surface of Pt and glass carbon electrodes using nanoscale zeolite particles as building block via a layer-by-layer (LbL) technique or by a secondary growth method. Compared to conventional zeolite-modified electrodes, the nanozeolite film modified ones (nanoZMEs) prepared by these methods exhibit good membrane morphologies with controllable thickness in nanometer scale and large zeolite/electrode contact areas due to the nanoscale zeolite film attached directly to the electrode. Ag +, Cd 2+ and Pb 2+ were selected as examples to evaluate the electrochemical performance of nanoZMEs with designed thickness. With the same thickness of zeolite layer, nanoZMEs prepared by the LbL technique possess short preconcentration and response time, while nanoZMEs fabricated through the secondary growth method exhibit high accumulation ability and ion exchange selectivity. It is found that besides the inherent ion exchange selectivity of the zeolite layer, the transport rate of ions in the zeolite layer toward the electrode surface is an important factor that affected the electrochemical selectivity of the ZMEs.