Micro-nano scale synchronous "carving" of viscose fiber in activation process for atmospheric hydrogen storage

Abstract

As an important branch of hydrogen storage materials, adsorptive materials have unique advantages such as high reversibility, fast adsorption rate and mild release conditions, etc. At present, the research on adsorptive hydrogen storage materials mostly focus on the pressure conditions of 30–300 bar, while the atmospheric hydrogen storage performance of adsorptive materials needs to be further enhanced. Based on the sonication-assisted activation process, micro-nano scale synchronous "carving" of viscose fiber was achieved in activation process for viscose fiber after carbonization, and petaloid activated carbon fibers (FL-VACFs) and rod-shaped activated carbon fibers (RL-VACFs) were constructed. Specific surface area of FL-VACFs and RL-VACFs can reach 1085.77 m2 g−1 and 956.81 m2 g−1 respectively, and the ultramicropore relative contents can reach 44% and 52.08% respectively. Under the synergistic action of abundant ultramicropores and oxygen-containing functional groups, FL-VACFs and RL-VACFs exhibit excellent hydrogen storage density of 2.04 wt% at77 K, 1 bar. Additionally, Multisite-Langmuir model (N = 3) model is discovered more suitable for accurate describing the hydrogen adsorption process of FL-VACFs and RL-VACFs under atmospheric pressure.