Facile preparation of poly(indole/thiophene) for energy storage and sensor applications

In this paper, a series of monomers (M1-M7) were facilely synthesized by Passerini reaction and the subsequent in-situ polymerization led to the formation of the conductive poly(indole/thiophene)s (P1-P7). Among P1-P7, it was found through the comparison that P7-P with a higher conjugated system exhibits an outstanding specific capacitance of 1170 F g⁻¹ (scan rate 1 mV s⁻¹), power density of 2614.4 W kg⁻¹ and energy density of 56.5 Wh kg⁻¹ (5 A g⁻¹). The capacitance performance of P7-P complexed with Fe³⁺ system is further increased by 130 F g⁻¹ because of the redox reaction of Fe³⁺. Using the chronoamperometry, the minimum detection limit of polymer P7-P for Fe³⁺ is 3 × 10⁻⁵ M. In summary, the facile synthesis of the conductive poly(indole/thiophene) polymers, their excellent energy storage and Fe³⁺ detection performance, open an opportunity for functional polymers in the energy storage and sensor applications.