Ti atomdoped single vacancy silicene for hydrogen energy storage: DFT study

Hydrogen adsorption on titanium (Ti) atom-doped single vacancy silicene (SV-SL) is investigated through first principles density functional theory (DFT) study. Strong hybridization of d-orbitals of Ti atom to p-orbitals of Si atoms results in a tight bond to the silicene sheet with energy of -6.48 eV and keeps away from metal clustering. Maximum 8 H-2 molecules firmly bind to Ti atom-doped SV-SL sheet with an adsorption energy ranging from -0.481 to -0.201 eV per H-2 molecule and hydrogen storage capacity (HSC) of 6.3 wt%. Double-side H-2 adsorptions on hollow sites of Ti atom-doped SV-SL sheet are verified by structural and electronic properties. The partial density of states (PDOS) analysis shows the kubas interaction mainly caused the molecular H-2 adsorption. Further, the absence of spin-up and spin-down channels in electronic band structures of nH(2) molecule adsorption to Ti atom-doped SV-SL systems indicates its nonmagnetic nature. Conclusively, this study reveals that the Ti atom-doped SV-SL can be a promising candidate for hydrogen storage applications.

Automated summary

The study shows that titanium-doped single vacancy silicene has promising hydrogen storage capabilities, with strong bonding to hydrogen molecules, moderate adsorption energy, and non-magnetic properties, making it a potential candidate for hydrogen storage applications.