Antidehydration Organogel Electrolytes Based Electrochemical Sensor for Self-Powered Flexible NO2 Detection.

Abstract

Flexible electrochemical gas sensors are promising for wearable electronics, yet conventional hydrogel electrolytes suffer from water evaporation, interfacial instability, and performance degradation under long-term operation. Here, we report a self-powered flexible NO2 electrochemical sensor based on a zinc-air battery (ZAB) structure using a poly(4-acryloylmorpholine)-sodium bis(trifluoromethanesulfonyl)imide-propylene carbonate (PACMO-NaTFSI-PC) organogel electrolyte. The nonvolatile organogel effectively suppresses solvent evaporation and eliminates dehydration-induced failure associated with conventional hydrogels. Meanwhile, the high dielectric constant of propylene carbonate promotes ionic dissociation, while weakly coordinated TFSI- anions optimize Zn2+ solvation and accelerate ion transport within the organogel network. The optimized sensor exhibits excellent environmental stability together with high NO2 sensing performance, including a sensitivity of 1158.9 nA/ppm, rapid response/recovery times of 25.6/19.5 s, and a low detection limit of 3.6 ppb. This work provides a viable strategy for developing highly stable self-powered flexible gas sensors for wearable sensing applications under harsh operating conditions.