Synthesis, characterization, and electrocatalytic properties of a custom-designed conjugated polymer with pyridine side chain

A newly designed conducting polymer (poly(N(-pyridin-4-ylmethyl)aniline)), POB), having a polyaniline backbone and pyridine pendant groups, has been electrosynthesized and studied in this paper. The characterization predominantly focuses on the possible application of the polymer-modified electrode in electrochemical fuel generation (H2 production and CO2 reduction). POB can be regarded as a pyridine-based electrocatalyst (mediator) immobilized on an electrode surface as part of a conjugated polymer, as confirmed by the appearance of a redox wave centered at E = −0.53 V (vs. Ag/AgCl) on the cyclic voltammogram of POB. The effects of experimental conditions (pH of the electrolyte, layer thickness, and material of the substrate electrode) on the immobilized pyridine-ring electrochemistry have been carefully analyzed, to understand the underlying factors governing the electrochemical behavior of this new functional material. Finally, the electrocatalytic behavior of POB was tested towards CO2 reduction and H2 evolution.