From a sustainable poly(benzoxazine-co-chitosan) to an ultrahigh-surface-area porous carbon electrode with a nano-engineered graphitic framework for a supercapacitor

Abstract

A porous carbon electrode was prepared based on poly(benzoxazine-co-chitosan), with synperonic-NP30 (a non-ionic surfactant) and KOH-activation used to enhance the topological properties. The microstructure was nano-engineered using an Ni-based graphitization catalyst. The computational analysis and Fourier-transform infrared spectroscopy uncovered the presence of hydrogen bonding between benzoxazine and chitosan, enhancing thermal stability. Adding non-ionic surfactant increased the pore volume and surface area; various average pore diameters were obtained (3.1–10.7 nm). Activation achieved a surface area of 1,928 m2 g−1 and a pore volume of 1.37 cm3 g−1. At 0.25 A g−1, the sample with 0.050 M of non-ionic surfactant had improved capacitance of 145.2 F g−1 which increased to 519 F g−1 upon activation. The Ni-graphitization yielded graphitic porous carbon exhibiting the best cyclic performance of 142.5 %. Such improvement arose from the increased surface area, a balanced volume of mesopores and micropores, and the presence of a graphitic framework.