Structural and surface modification of carbon nanotubes for enhanced hydrogen storage density

Abstract In this paper, we report the synthesis of functionalized carbon nanotubes (F-CNTs) by acid treatment and their hydrogen storage properties. These F-CNTs have been characterized by XRD, FTIR, Raman spectroscopy and electron microscopy techniques. The results show that the structure and morphology of P-CNTs have been modified after the acid treatment. The hydrogen storage capacity was determined by volumetric measurements at room temperature and experimental results showed that the storage capacities of P-CNTs and F-CNTs were 0.65 wt% and 0.89 wt%, respectively. A notable enhancement in hydrogen storage capacity of F-CNTs was observed which could be attributed to the enhanced oxygen functionalities, opening of end caps and presence of surface defects that offered enhanced surface area for hydrogen adsorption. The key results of present research show that structural, morphological and chemical changes are responsible factors to enhance the hydrogen storage density.