Green Fenton-like Synthesis of Anion-Tunable PEDOT Conductive Powders for Flexible Bioelectronics

Conventional chemical oxidative polymerization of EDOT to produce pristine PEDOT conductive polymers has several critical drawbacks, including long reaction times, high oxidant consumption, low product purity, severe environmental pollution, and low conductivity (<1 S/cm). These limitations hinder the use of pristine PEDOT in high-performance flexible bioelectronics. In this work, we address these challenges by developing a green and efficient Fenton-like oxidative polymerization strategy using hydrogen peroxide as the oxidant and a trace amount of iron salt as the catalyst. This radical-mediated process generates no harmful byproducts. The conductivity and yield of the resulting PEDOT powders are influenced by the acid dosage, reaction time, iron concentration, and oxidant amount. The resulting neutral PEDOT powders exhibit high purity, uniform particle size, good aqueous dispersibility, low residual iron content, and a moderate conductivity of 6.5 S/cm. Based on these properties, we fabricate a physically cross-linked biohydrogel through a freeze–thaw process using PEDOT powder, poly(vinyl alcohol) (PVA), and a small amount of tannic acid (TA). The resulting PVA/PEDOT/TA/Fe3+ hydrogel exhibits excellent stretchability, adhesion, electrical stability, and biocompatibility. Overall, this work provides a green and versatile platform for developing high-performance PEDOT-based hydrogels, with potential applications in wearable bioelectronics, including skin-mounted sensors, medical patches, and neuromuscular stimulators.