Poly(carbazole-co-1,4-dimethoxybenzene): Synthesis, Electrochemiluminescence Performance, and Application in Detection of Fe³⁺

In this study, four polycarbazole derivatives (PCMB-Ds) with different alkyl side chains were designed and synthesized via Wittig–Horner reaction. A novel solid-phase electrochemiluminescence (ECL) system was prepared by immobilizing PCMB-D on an indium tin oxide (ITO) electrode with polyvinylidene fluoride (PVDF) in the presence of tripropylamine (TPrA). It could be found that the increase in alkyl side chain length had little effect on the ECL signal of PCMB-D, while the increase in the degree of polymerization (DP) greatly enhanced the ECL signal. Furthermore, the P-3/ITO ECL sensor based on the polyoctylcarbazole derivative (P-3) with the best ECL performance was successfully constructed and detected Fe3+ under the optimal experimental conditions. The ECL signal steadily diminished with the increased concentration of Fe3+ because of the competition and complexation between Fe3+ and P-3 under the condition of pH 7.4. This P-3/ITO platform could realize a highly sensitive and selective detection of Fe3+ with a wide detection range (from 6 × 10−8 mol/L to 1 × 10−5 mol/L) and low detection limit of 2 × 10−8 mol/L, which could allow the detection of Fe3+ in multiple scenarios, and would have a great application prospect

Construction of Alkaline Gel Polymer Electrolytes with a Double Cross-Linked Network for Flexible Zinc–Air Batteries

Flexible zinc–air batteries have broad potential as the next generation of energy storage component in wearable electronic devices. However, the mechanical performance and ionic conductivity of electrolytes are urgent issues that hinder the commercial application of flexible batteries. Herein, the alkaline gel polymer electrolyte (AGPE) with a double-network structure is developed, which consists of a covalently cross-linked polyacrylamide (PAM) by in situ polymerization and a physically cross-linked poly(vinyl alcohol) (PVA) by the freeze–thaw method. The freestanding PVA/N-PAM/KOH gel electrolyte demonstrates high ionic conductivity (309.9 mS cm–1) and excellent mechanical toughness (0.69 MJ m–3), benefiting from the synergistic effect of the double cross-linked system and hydrogen bonds. Meanwhile, the assembled ″sandwich″-type zinc–air battery presents excellent power density (40.43 mW cm–2), long-term cycle life (113 cycles), super-high-energy efficiency (70.2%), and stable discharge plateau. Impressively, the PVA/N-PAM/KOH-based batteries attached to the human body surface are reliably capable of powering light-emitting diodes