A First-Principles Study on Titanium-Decorated Adsorbent for Hydrogen Storage

Energies

Weichun Cui¹  Weijie Yang²  Kai Ma²  Shuai Dong²  Yu Zhou²  Erfei Lv²  Di Zheng²  Zhengyang Gao² 

[1] Department of Law and Political Science, North China Electric Power University, Baoding 071003, China;Department of Power Engineering, North China Electric Power University, Baoding 071003, China;

关键词: hydrogen storage;    first-principles;    graphene;    titanium decoration;    adsorption;   

DOI  :  10.3390/en14206845

来源: DOAJ

【 摘 要 】

Based on density functional theory calculation, we screened suitable Ti-decorated carbon-based hydrogen adsorbent structures. The adsorption characteristics and adsorption mechanism of hydrogen molecules on the adsorbent were also discussed. The results indicated that Ti-decorated double vacancy (2 × 2) graphene cells seem to be an efficient material for hydrogen storage. Ti atoms are stably embedded on the double vacancy sites above and below the graphene plane, with binding energy higher than the cohesive energy of Ti. For both sides of Ti-decorated double vacancy graphene, up to six H₂ molecules can be adsorbed around each Ti atom when the adsorption energy per molecule is −0.25 eV/H₂, and the gravimetric hydrogen storage capacity is 6.67 wt.%. Partial density of states (PDOS) analysis showed that orbital hybridization occurs between the d orbital of the adsorbed Ti atom and p orbital of C atom in the graphene layer, while the bonding process is not obvious during hydrogen adsorption. We expect that Ti-decorated double vacancy graphene can be considered as a potential hydrogen storage medium under ambient conditions.

【 授权许可】

Unknown