The development and utilization of renewable energy sources have been encouraged over the past few years owing to the strict measures imposed on the use of fossils fuels as a way of controlling and mitigating greenhouse gases emissions and environmental pollution. Interestingly, hydrogen energy has been identified as an excellent alternative to fossils energy thus attracting significant attention of researchers. Unfortunately, the development of efficient hydrogen storage technologies has remained a challenge thereby reducing hydrogen energy exploration.
In a recently published literature, the advancement in nanotechnology has opened new ways for design and enhancement of hydrogen storage due to their excellent properties including large-surface-to-volume ratio and lightweight. This is attribute to the use of carbon-based nanostructures such as graphene, fullerenes and carbon nanotubes. Alternatively, hydrogen storage using these materials have been enhanced by doping of lightweight alkali metals to improve hydrogen binding energy. More recently, new structures combining the basic individual nanostructures have been established. For instance, fullerenes sandwiched between graphene sheets significantly enhanced hydrogen gravimetric density. The same has been extended to other metals like lithium and sodium which are promising materials for increasing hydrogen storage capacities.
To this note, Nanjing University of Posts and Telecommunications researchers went an extra mile to explore hydrogen storage capabilities of fullerenes and carbon nanotubes. In particular, a three-dimensional nanostructure comprising of fullerenes and carbon nanotubes was designed. The hydrogen storage capacity of the resulting material was then investigated. Their research work is currently published in the research journal, International Journal of Hydrogen Energy.
In brief, the nanostructure design entailed using lithium and boron doping to interconnect the fullerenes and carbon nanotubes. Next, their geometric and thermal stability was verified through first principles of dynamic simulations and density functional theory. Eventually, they further investigated the hydrogen gravimetric storage density and average hydrogen energy adsorption and compared them to the set targets.
The authors observed significant improvements in the metal binding as well as average binding energy attributed to boron substitution thus eliminating the problem associated with lithium clustering. Consequently, a higher hydrogen storage gravimetric density of 15.9wt% was recorded indicating a higher value than some of the set targets while the average adsorption energy, on the other hand, fell on the desired range between 0.18 to 0.27eV.
In summary, scientists of Nanjing University of Posts and Telecommunications led by ZH. Yang, YH. Wang and L. Bi successfully demonstrated the feasibility of fullerenes and carbon nanotubes hybrid interconnected by lithium decoration and boron doping in enhancing hydrogen storage. To actualize their study, they further investigate the effects of pressure and temperature on the adsorption of hydrogen on the proposed design. In general, the simulations results indicated that the proposed nanostructures are a promising solution for enhancing hydrogen storage which is a key requirement in hydrogen energy development. Therefore, it will further advance the development of renewable energy sources for a sustainable economy.
Bi, L., Yin, J., Huang, X., Ren, S., Yan, G., & Wu, Q. et al. (2019). Lithium decoration of boron-doped hybrid fullerenes and nanotubes as a novel 3D architecture for enhanced hydrogen storage: A DFT study. International Journal of Hydrogen Energy, 44(5), 2934-2942.Go To International Journal of Hydrogen Energy