Preheated self-aligned graphene oxide for enhanced room temperature hydrogen storage

This study explored the hydrogen adsorption capacity of self-assembled aligned graphene oxide at room temperature. The characteristics of as-prepared graphene oxide were determined by scanning electron microscopy, Raman spectroscopy, and X-ray diffractometry techniques. Three different temperatures were taken for preheating, i.e., 25, 250, and 400 degrees C. The maximum adsorption pressure was given to 20 bar, and we evaluated the hydrogen adsorption competency at room temperature (25 +/- 2 degrees C). The maximum hydrogen storage capacity was achieved similar to 2.5 wt%, which was found for the graphene oxide sample preheated at 400 degrees C. This hydrogen storage capacity was 67% and 40% more than the graphene oxide samples preheated at 25 and 250 degrees C, respectively. Such an enhancement of hydrogen storage capacity in the self-aligned graphene oxide samples at room temperature is attributed to reduced interlayer spacing and increased topological defects in preheated graphene oxide samples at 400 degrees C. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.