Hydrogen storage and release material and method of producing same

A material for reversible hydrogen storage and release, the material comprising:

• a two-dimensional hydrogen boride-containing sheet including a two-dimensional network containing n(HxBy) (n≥4, 0.001≤x/y≤0.999) having a molar ratio of boron to hydrogen of from 1:0.999 to 1:0.001, the molar ratio being determined by thermal desorption spectroscopy, and mass measurement before and after temperature rise,
• wherein the material for reversible hydrogen storage and release:
• has peaks derived from B1s of boron at 187.5±1.0 eV and 191.2±1.0 eV to 193±1.0 eV in X-ray photoelectron spectroscopy, and
• has a peak derived from a B-H stretching vibration at from 2400 cm−1 to 2600 cm−1 and also has a peak derived from a B-H-B stretching vibration at from 1200 cm−1 to 1800 cm−1 in infrared spectroscopy,
• wherein
• the material for reversible hydrogen storage and release reversibly stores and releases hydrogen,
• the material for reversible hydrogen storage and release releases hydrogen by being heated to from 120° C. to 450° C., and
• the material for reversible hydrogen storage and release that has released hydrogen, stores hydrogen by bringing the material into contact with water, and
• wherein the two-dimensional hydrogen boride-containing sheet has a mesh-shaped planar structure in which:
• boron atoms are arranged in a cyclic hexagon,
• a plurality of the hexagons formed by the boron atoms are connected to each other, and
• hydrogen atoms are randomly bonded to the boron atoms forming the plurality of the hexagons, without having specific periodic regularity and without aggregating.