Hydrogen Storage Properties And Release By Compress Of Li Doped Silicon Nanostructures

Two kinds of silicon nanostructures SiNR and SiM-SiNT with proteiform pores are constructed and investigated about their hydrogen storage and release properties. Li atom doping is introduced to study its promotion to hydrogen storage and pore size’s effects on their hydrogen storage properties are also seriously discussed. Additionally, the structures’ flexibility facilitates us to deform them by external force, which means that these new structures are promising candidates not only for hydrogen storage but also hydrogen release by deformation without destruction to the structures, which ensures their cyclic utilization in hydrogen storage and release. So the investigation of hydrogen release by compress is carried out after the discussion of their hydrogen storage properties.In this work, we investigate hydrogen storage and release properties of these two kinds of structures with grand canonical Monte Carlo (GCMC) simulation method. For the hydrogen storage, our work mainly focuses on how their hydrogen storage properties are affected by the doping ratio of Li atoms and their pore size and finding the optimal combination of these two factors to maximize their hydrogen storages. For the hydrogen release, we principally investigate the feasibility of release hydrogen by compressing structures. Simultaneously, strict comparison is made about hydrogen storage and release properties between these two kinds of silicon nanostructures.Our study indicates that there is always an optimal combination of Li doping ratio and structure pore size which makes a SiNR hit its maximum hydrogen storage and there is also an optimal doping ratio for either SiNR or SiM-SiNT when its pore size is constant. Our study also indicates compression is an effective method for SiNR to thoroughly release hydrogen without structural destruction but it destroys SiM-SiNT just after only a few hydrogen molecules are released. Which maybe imply that only nanostructures with adequate flexibility suitable for releasing hydrogen by deformation.