Facile construction of a click-based robust porous organic polymer and its in-situ sulfonation for proton conduction

Abstract

A triazole-based porous organic polymer (TaPOP-1) was successfully synthesized by the judicious “click” combination of tetrahedral azide-containing and triple-symmetrical acetylene-containing modules. Thermogravimetric analysis displayed that it possesses a thermal stability up to 180 °C. N2 sorption experiments before and after solvent immerging revealed that it is a robust organic polymer with a high porosity. Investigations of electrochemical impedance spectroscopy measurements revealed that when incorporating sulfonic acid into the clicked POP during the in-situ reaction process, a remarkable increase in proton conductivity proportionally to the ratio of the introduced sulfonic acids was observed, and the finally resultant sulfonated TaPOP–SO3H-3 displays a proton conductivity of 0.92 × 10−2 S cm−1 at 353K under 98% Relative Humidity (RH), nearly 4 orders of magnitude enhancement than the value of the pristine TaPOP-1 (6.7 × 10−6 S cm−1) at the same condition. This work demonstrates that utilizing the versatile “click” reaction, not only robust porous materials can be facilely constructed, but also highly promising candidates of proton-conductive electrolytes can be achieved via in-situ grafting strong acids into the skeletons of porous materials.