Increase in H2 storage capacity of nanoporous carbon fabricated from waste rice husk via improving the mode of the reaction mixture cooling down

Abstract

Nanoporous carbon (NPC) with high hydrogen storage capacity was fabricated from rice husk. The rice husk was activated using KOH, and the cooling step during the KOH activation process was varied. The specific surface areas, pore size distributions, and hydrogen storage capacities of the fabricated NPC samples were determined. We found that while the specific surface area did not change with the choice of the cooling process, the pore size distribution did. Furthermore, in the case of rapid cooling, the maximum hydrogen storage capacity at 77 K was 7.2 wt%, while that for natural cooling was 5.5 wt%. Thus, it can be concluded that the cooling procedure used during the KOH activation process determines the hydrogen storage properties of the thus-fabricated NPC materials.

Keywords

• Nanoporous carbon
• Alkali activation treatment
• Rice husk
• KOH
• Rapid cooling
• Hydrogen storage