Spider silk-derived nanoporous activated carbon fiber for CO2 capture and CH4 and H2 storage

Abstract

High surface area porous carbon with fibrous microstructure offers a broader application potential than powder form. However, controlling the microstructure with high porosity is difficult, and if possible then through a complex and time-consuming synthesis method. Herein, the development of high surface area nanoporous activated carbon fiber by activating spider silk (natural biomaterials) using potassium hydroxide is being reported. The specific surface area (SSA) and total pore volume for the developed material were 2730 m2/g and 1.56 cc/g, respectively, and its surface contain high oxygen content. Its high SSA and oxygen-rich surface provide an enhanced CO2 capture and energy carrier gases (H2 and CH4) storage capacity. The CO2 capture capacity at 0 °C and 25 °C, 25 bar, were estimated to be 23.6 and 15.4 mmol/g, respectively, among the highest reported values for porous carbon fiber. Moreover, the developed sample has shown the CH4 storage capacity of 8.6 mmol/g at 0 °C, 25 bar, and for H2, it was 4.1 wt% at − 196 °C, 25 bar. In addition, the developed carbon material demonstrated an easy regeneration and almost negligible loss in uptake capacity, confirmed by adsorption-desorption cycles. The observation of high porosity and promising gas storage and recyclability in spider silk-derived activated carbon fiber indicates that the employed method can effectively convert biomaterials into high surface area activated carbon fibers for advanced energy and environmental applications.