Introducing Noble Gas as Space Holder under High Pressure to Design Porous Titanium Carbides with Open Metal Sites for Hydrogen Storage at Near-Ambient Conditions.

It has been a long-standing challenge to develop high-performance solid-state hydrogen storage materials operated under near-ambient conditions. In this work, we propose a new strategy of using noble gases for space holding to design porous titanium carbides with abundant open metal sites for hydrogen storage. By using machine learning and graph theory-assisted universal structure searching methods, we obtain 28 porous titanium carbides from three precursors (TiC dimer, C atom, and Kr atom) under 30 GPa of pressure.

Hydrogen Adsorption on Type-5 Penta-MgN Sheet, Nanotube, and 3D Porous Structure.

Motivated by the recent report on penta-MgN sheet [ , 38, 101259] that is the first realization of type-5 pentagonal 2D tessellation with exposed regularly distributed Mg ions, we carried out density functional theory studies on the interactions of H molecules with 1D penta-nanotube, 2D penta-sheet, and 3D porous structures based on penta-MgN. We found that when the penta-MgN sheet is assembled to a 3D porous structure or curved to a nanotube, the bandgap increases from 1.18 to 1.

The relationship between activated H2 bond length and adsorption distance on MXenes identified with graph neural network and resonating valence bond theory.

Motivated by the recent experimental study on hydrogen storage in MXene multilayers [Liu et al., Nat. Nanotechnol.