Physics

Molecular orbital

Electron

Chemical bond

Organic chemistry

Absorption (acoustics)

Density functional theory

Computational chemistry

Band gap

Atomic orbital

Composite material

Chemistry

Metallurgy

Materials science

Boride

Molecule

Quantum mechanics

Optoelectronics

Photochemistry

Antibonding molecular orbital

Nature Communications

Hydrogen boride nanosheets (HB sheets) are facilely synthesized via ion-exchange treatment on magnesium diboride (MgB 2 ) in an acetonitrile solution. Optical absorption and fluorescence spectra of HB sheets indicate that their bandgap energy is 2.8 eV. According to first-principles calculations, optical absorption seen at 2.8 eV is assigned to the electron transition between the σ-bonding states of B and H orbitals. In addition, density functional theory (DFT) calculations suggest the other allowed transition from the σ-bonding state of B and H orbitals to the antibonding state with the gap of 3.8 eV. Significant gaseous H 2 release is found to occur only under photoirradiation, which causes the electron transition from the σ-bonding state to the antibonding state even under mild ambient conditions. The amount of H 2 released from the irradiated HB sheets is estimated to be 8 wt%, indicating that the sheets have a high H 2 -storage capacity compared with previously reported metal H 2 -storage materials.

Photoinduced hydrogen release from hydrogen boride sheets