Ion‐selectivity of polypyrrole carbide‐derived carbon films in aqueous electrolytes

摘要

Abstract In this work, we have combined polypyrrole (PPy) doped with dodecylbenzene sulfonate (DBS−) and carbide‐derived carbon (CDC), forming PPyCDC (PPy/DBS‐CDC) composites. Scanning electron microscopy revealed for PPyCDC that most CDC particles are located on the surface of the films. This work's main goal is to investigate the ion‐selectivity of the novel PPyCDC composite by linear actuation studies, with primary actuation taking place at discharging. Four different aqueous electrolytes are applied with hydrophobic cations, such as TMA+ (tetramethylammonium ion) and EDMI+ (1‐ethyl‐2,3‐dimethyl imidazolium ion). They are hydrophilic with Li+ (lithium‐ion) and Na+ (sodium ion). It was possible to distinguish each cation from linear actuation studies, either cyclic voltammetry or square wave potential steps. In the case of pristine PPy/DBS, that ion differentiation could not separate. Chronopotentiometric measurements of both films (PPyCDC and PPy/DBS) were performed. It could control (read) the strain for PPyCDC films and the potential at constant current density. The electrical energy adapts to exchange cations, forming a sensor device with ion‐selectivity of the applied cations considering their hydrophilic and hydrophobic characteristics. The best specific capacitance (energy storage) is found for EDMI+ cations in PPyCDC films with 193 F g−1, enabling this composite in multifunctional applications.