A synergistic approach: cellulose nanocrystals blended polyimide-based covalent organic framework for advanced supercapacitors and hydrogen evolution

Polyimide-based covalent organic framework (PI-COF) materials merge the durability of polyimide with the extensive surface area and adjustable pores typical of COF materials. Cellulose nanocrystals (CNC), highly versatile, require precise reaction condition optimization for cost-effectiveness, purity, selectivity, and performance enhancement. In this work, evaluate the performance of supercapacitors using a novel hybrid electrolyte (PI-COF/CNC) through electrochemical studies and hydrogen evolution reactions (HER) (Tufail et al. in Energy. Mater. Adv. 4:0015, 2023). This hybrid approach facilitates an enhanced charge transfer pathway and expands the availability of electroactive sites, leading to significant improvements for electrochemical applications. A significant specific capacity of 2162 C/g was demonstrated by the PI-COF/CNC composites at a current density of 1.0 A/g. Interestingly, the PI-COF/CNC//AC device exhibits capacity retention 84.7% and columbic efficiency 91.6% after 15,000 cycles, demonstrating its stability and durability. When compared to each of the materials evaluated, the PI-COF/CNC composite showed exceptional catalytic capacity in the hydrogen evolution process (HER), obtaining the lowest Tafel slope of 41 mV/dec.