Hydroxyl-functionalized microporous polymer for enhanced CO2 uptake and efficient super-capacitor energy storage
By Nazeer, Ahmed Abdel; Husain, Ali A.; Samuel, Jacob; Rajendran, Narendran; Makhseed, Saad
Published in Reactive and Functional Polymers
2020
Abstract
In recent years, porous organic polymers (POPs) have received increasing attention and research interest due to their formidable potential applications in gas storage/separation, heterogeneous catalysis, photoelectricity, energy storage and conversion, etc. In this work, we report the design and synthesis of a hydroxyl-functionalized porous organic polymer (PCz-res) by conventional FeCl3-facilitated oxidative polymerization for gas adsorption and energy storage applications. The precursor Cz-res was designed and synthesized by the imidization of anhydride bearing twisted carbazole units with 4,6-diaminoresorcinol. The prepared PCz-res polymer was completely characterized by the usual analytical techniques. PCz-res exhibited a high specific surface area of 1015 m2/g and reversibly adsorbed 20.53 wt% (273 K) and 14.92. wt% (295 K) CO2 at 1 bar with a moderate isosteric heat of CO2 adsorption (22.39 kJ/mol). The favourable properties of PCz-res were attributed to the uniform pore size distribution (0.8 nm), high surface area, rich nitrogen content and presence of polar CO2-philic hydroxyl groups in the polymeric network. These features make the investigated polymer a plausible emerging material in the field of gas adsorption and separation. Moreover, PCz-res was applied in supercapacitor energy storage and exhibited a specific capacitance as high as 434 F g−1 in 1 M H2SO4 at a 2 mV/s scan rate and 367 F g−1 at a current density of 0.5 A g−1. Additionally, PCz-res retained 91% of the initial specific capacitance after 2000 charge/discharge cycles at a current density of 10 A g−1. The structural characteristics of PCz-res lead to a larger accessible surface area and a redox-active structure, resulting in efficient charge energy storage.