Multiscale molecular dynamics investigation of high-efficiency hydrogen storage in titanium-doped carbon nanotubes.

This study investigates the hydrogen storage performance of titanium-doped carbon nanotubes (Ti-CNTs) through a multiscale simulation framework that integrates electronic structure calculations, atomic-scale dynamics, and macroscopic property analysis. A pressure-modified Lennard-Jones (LJ) potential function was developed to simulate hydrogen adsorption behavior in (12,12) armchair-type and (24,0) zigzag-type single-walled carbon nanotubes (SWCNTs) under a pressure of 3 MPa. Simulation results reveal that 5% Ti doping in (12,12) CNTs yields a hydrogen storage density of 8.04 wt.% at 77 K (i.e., approximately four times greater than the undoped counterpart). Furthermore, the system maintains over 90% capacity retention after 100 adsorption-desorption cycles. The proposed multiscale strategy, combined with the pressure-doping synergistic optimization mechanism, offers a systematic approach for the rational design of stable and efficient hydrogen storage materials, demonstrating potential for practical engineering applications.